For those of you who don't want to read the whole guide, I've tried to put the most important things down that were completely “I wish I would have known this sooner” items below:

1. You can right-click and select "More Info" on almost every item in the game. This gives you information about how or if the item is used in crafting or for gifting to a special NPC which is very important to know when you have inventory issues early on and absolutely imperative later on when you are grinding Favor with certain NPCs. Remember the PG adage for determining if you should keep an item: Craft → Favor → Barter → Sell.
2. The people/locations in Serbule that provide you with inventory space at higher and higher Favor levels are: Joeh, Marna, Tadion, Ivyn (specifically his Chest), & Charles Thompson. In Serbule Hills, you get inventory with Baroness Marith Felgard, Julius Patton, Sammie Grimspine, & Tyler Green at higher favor levels. At the Casino it is: Kib the Unkillable, Otis, Qatik, Ragabir, Tavilak, Mandibles, & Willem Fangblade. Nearby in Rahu it is: Ashk the Answerer, Ichin the Ice Master, Daniel Murderdark, and Nishika. There are others that have space as well, but given that the demo is in the first two areas and the combo of Rahu/Casino gives the biggest space in the game, I feel it's necessary to focus on these locations first.
3. Once you have about 6-10k in councils saved up, ask for a high level Tailor to create you some Cargo Gear WITHOUT pockets. Or join a guild and ask your guild's Tailors to make you some Cargo Gear for a small donation. This is essential gear to use till you have enough Favor with the NPCs listed above to provide storage space. If you have another 6-10k to have them add pockets, offer 12-20k for a pocketed set. Most Tailors don't mind helping newbies, but the ones in your guild are going to be far more responsive and will likely even do it for free if they aren't inundated with requests.
4. You need to level up your Death skill by dying in unique ways early on in the game. Yes, you read that correctly. If you are one of the main races and not an animal or Fae, you need to die a lot early on to get your Death XP high enough to use a very powerful mechanic in the game. Enter The Light can be used to portal to Serbule or Rahu every 8 hours. I often recommend using it at the start and end of every gaming session to position yourself what you are doing that gaming session or for the next time you log in. When your skill in Death reaches level 10, you can use portals in the Death Zone to go straight to Serbule or Rahu once every 8 hours. Words of Power or drinking Fuel Oil can be used to give you instant deaths or to otherwise make going here easier. Regular Iocaine Powder (not Practice) kills you and is also fine to use. Both portals have a separate 8 hour cooldown. You can also buy a Gemstone Hammer and a few other useful items in the Death Zone if you need them.
5. There is a secret entrance to the Casino that you can get to by jumping on the rocks to the right of the Casino back door in Eltibule. You are expected to find this on your own, but it's pretty important to know about this employee entrance early on. By combat level 30 you should be regularly using it and starting to get Favor with many of the Casino NPCs.
6. Click on the animal face icon to bring up a pet menu. A lot of people won't talk to you if you bring necro pets into town and oftentimes you'll want to change your pet strategy. This menu lets you change how your pets interact in the world. Most players either forget this from having a rat pet on tutorial island or do not see this icon or understand what it is till they become a pet class of some sort.
7. Go through settings and keybinds under Graphics settings. To reduce graphics lag during large events, go to Settings then GUI and uncheck the Show Combat Numbers option there. This is a nigh-mandatory setting to change for when zone events are taking place (large numbers of players). While there, also turn on Always Show Interactable so you can see everything on the ground while playing. To make Gardening and Looting very much easier, you are going to want to go to Settings then Keys and change Select Next Non-Combatant to a key. Then set Use Selected and set it to another key. Be sure to adjust your camera while Gardening to look straight down on your plants only. In the Casino, watch out for wandering Cows that may steal your focus while rotating through your plants using these two keys or you'll replace empty bottles with Milk. Also there are key binds that you can use to auto loot, auto butcher, auto skin, and auto bury corpses.
8. Speed potions are learned from Ignite the Fire in Your Legs sold by Yetta in Eltibule. These are early Alchemy recipes that only require a few relatively easy items to make: a Bottle of Water, Fire Dust, Clownfish Fillet or Perch Fillet, and Sugar. They are imperative when doing Surveying for fast surveys and maintain their importance in the mid to late game as well. Horses, or more specifically the Riding skill, can be learned by paying money or doing a quest with an Elf in Hogan's Keep in North Eltibule, but you'll still want these speed potions for getting around early-mid game and inside dungeons. They are also very much needed for Hardcore mode.
9. You can use Rubywall Crystals in your crafting recipes for armor and weapons. In fact, you'll almost certainly need to use them in your crafting recipes if you are doing a bunch of Work Orders. They are great for making gear without combat level requirements, too. If you are a newbie, doing Surveying for Rubywall Crystals is probably the best way to make money early on because of how well these Crystals sell and how easy they are to farm. Mid-to-Late-game crafters still need these crystals for their Work Orders and can't be bothered to run around Surveying so they are oftentimes willing to buy them, sometimes even at a significant premium to their real price.
10. Complete Work Orders for money. While the early Work Orders may seem like a complete waste of time and resources (especially all the Oak Wood recipes), it is essential that you level your Industry skill to handle the later Work Orders as these can eventually become the primary way you can make money from your crafting skills. They are great for justifying the leveling you are going to be doing just to level these skills anyway as well. I've heard all sorts of comments from players that say they never do Work Orders and I disagree that completely forgoing Work Orders is the proper route to play the game. There is one exception to this, however, and that is if you never do crafting whatsoever in any MMORPG you play. If you never plan on being any sort of crafter, then maybe that's viable, but if you are going to do any form of crafting, you might as well do Work Orders for what you are crafting. Not only do high level work orders get you the best money gains in the game (especially late game) but they also train you. I personally love crafting in the game and love how each of the different combat/crafting skills have synergy buffs with other combat/crafting skills. The total package is what makes the game unique and fun and work orders are just a part of that fun and help you build money.

You can think of these as “Runner-Up” things that are also important, possibly even just as essential as the list above.

1. You absolutely need to get a set of no-level-requirement pocketed Tailor gear with at least +20 or more inventory slots on it. If you have to buy it in the player vendor stalls or join a guild or do favors outside of the game, you simply need a set of this gear in order to seriously play the game, otherwise most of your time will be spent just ferrying items or you will have to store your buff items mostly in your base instead of on your person. Just join a guild and ask for +inventory space gear now. Any guild should be happy to do it for new players. If not, beg in General chat if someone will craft you some with your specific combat skills for 18-22k councils or so, or maybe 10-12k for a non-specific cargo set. Yes, I know I said this in the top ten above, but I'm reiterating it here because new players don't often realize the power of cargo gear sets. The longer you can stay out fighting, the faster you can level and if you are having to do inventory stops often, you're not leveling. With solid and consistent dedicated play, you should be able to make level 40 in two combat skills in under 20 hours of play time.
2. You can run from Rahu to the Ilmari Desert Portal somewhat safely by hugging the northern border of the map. You will still run into Evil Beggars sometimes just outside of Rahu on your way to the Rahu desert entrance, but they can be handled pretty safely at level 40 and avoided safely at earlier levels, too. Once in Ilmari (you'll be in the middle north of the map), you can use Tab to find the nearest enemy as you run and avoid Grimalkins, Drakes, and the Manticores without too much trouble to make it to Amulna in the Middle Western portion of the map and the portal from Ilmari to Kur (in the southern middle). Amulna is an important early location to route out a path to for Leatherworking and Toolcrafting work orders if you are trying to level these skills. I have a full article on what I call the Work Order Run.
3. You are going to get overwhelmed by everything you can do when you first get past the newbie island. After the newbie island, the game really opens up super wide and you get overloaded with loot and quests and NPC favors and possible skills very easily. This can lead to “analysis paralysis” as you attempt to save meats, organs, skins, wood, mushrooms, food, and everything else that you find in the game in order to craft everything you can in the game. Don't. Save two of either meats, organs, skins, food, mushrooms, or wood, but not all of them. Later on you'll be able to save more, but not as a brand new player without inventory gear.
4. Focus on increasing Favor with the NPCs that give you inventory space in Serbule. While this seems like a repeat of the point in the top ten list, I will get into specifics here. The two most important and easiest NPCs to get Favor with first are Joeh and Marna for their inventory space. Marna will take your skins and Joeh will take sausages, both can be made or obtained from killing Pigs around Serbule. Fainor in the inn has the recipe for Sausages and it's pretty easy to get to the point of making them.
5. Focus on only two major combat skills that you like after level 30. You can mix and match and play around with different combat skills, but if you are still doing this at level 40, you're only hurting yourself, in my honest opinion. You should know by level 25 or at most level 30 if you like a skill enough to take it to level 80+
6. I picked only three major “Crafting” skills I wanted to be an expert at while leveling my two main combat skills and went with them: Gardening, Cooking, and Tailoring. You may do well to focus on the same three or maybe include Leatherworking instead of Tailoring and Carpentry instead of Gardening. If you don't mind doing surveys compared to Gardening, or especially if you plan to go Werewolf or Druid, I would recommend Surveying/Mining/Geology (Lycan/Werewolf), Blacksmithing (Lycan/Werewolf), and later, Toolcrafting (Druid), too. Cooking is pretty much a must-have skill for everyone due to Favor questing, and it is imperative for solo players. If you are in a duo, one person should probably focus on Gardening and Cooking.
7. NPCs will run out of gold, it has nothing to do with other players getting the vendor's gold, though. It sucks big time to not have an NPC buy anything from you early on. Everyone notices the money problem with Marna right away, too. You simply must get Favor increased with NPCs, not just for their inventory space, but also so that they will spend money buying your items. That first pig snout for Joeh is essential to gaining Favor with him. Keep in mind that every player has been through this, too, you are not a unique person to have run into this problem. Eventually these merchants will have so much money for you on a weekly basis that it will not be an issue unless you are grinding particularly hard.
8. Flia in Serbule will trade an Aquamarine gem for a Tuft of Fur and a Beak. You can get Tuft of Fur from the wolves in Kur and you can buy Beak from Way in the Mushroom Cave. Both can then be Bartered with Flia when she is at Best Friends (or Like Family?) Favor level for the gem. This makes Aquamarines and Rubywalls two of the best crafting gems for Work Orders and early gear if you aren't going to focus on Surveying. Bartering with Flia is an easy way to get a decent number of these gems without having to Survey. She also trades an Ancient Gold Coin for an art piece called “Esoteria” which is worth more money for its value than the painting by itself.
9. You can obtain easy Favor with Nightshade in Kur using Heartshrooms by converting them to Gur-Hortas in Sun Vale. Heartshrooms can be farmed in the Mushroom Cave early on. Store them and you can later turn them into Gur Hortas via bartering at Sun Vale with Yagreet. Enchanted Holly Seeds can also be bartered for them which is important for Toolcrafting and Druids.
10. The Sidebar can be used for a lot of good skills. You can pull many good abilities to your Sidebar for use. Most important of these are First Aid, Armor Patching, and Dig Deep, but there are plenty more (even Combat skills) that belong here for most loadouts. Stake the Heart is a particular handy one to have for mobs that need stunned.
11. Using a Shovel early on to bury corpses is important for learning Priest. This is somewhat of a major spoiler, but I feel like it should be mentioned or “rumored” to a new player in case they want to get that skill later on.
12. In addition to the Shovel, a good Skinning knife and a good Butchering knife are also important.
13. A forensic analysis toolkit or something to analyze dead mobs is also important early game.
14. Early players should avoid Angling, IMHO as this form of fishing is NOT a good use of your time. You can get a fishing pole from Roshun the Traitor in north Serbule, however.
15. Mineral Nodes can be mined in south Rahu to get Copper and other mining materials that you need mid-game. I think it's probably one of the best places to get Copper, too. The caveat to this is that the mobs here are super annoying to deal with and will kill you. Also, you will die of thirst, but death is just an annoyance compared to benefit you get from mining out this area once you are at mid-to-high level mining.
16. Once your Industry skill is high enough, you can “rent” space using the Retail Management skill in Serbule or the Casino. Or, you can pay like 20k to get to use the space. This is handy if you need space and you have mules and/or need just a little bit more space. Generally speaking, you can probably sell the excess goods you get anyway. Just remember that you pay a little bit more every day that you “rent” a shop space.
17. Speaking of renting shop spaces, have you ever wondered how so many high level players have their shops for so long? The trick is to pay the 20k to get Retail Management on an alt and then bring that alt or log into it while the Poetry Jam is running. You will get drunk, sure, but your alt can then get the Savvy Shopkeeper buff, which HALVES the cost of running a shop. Most players are going to hate me for explaining this, but it's important that you know about it. Then, you only need to log on as your alt every day to re-up the cost of the vendor stall and for like 1k-3k per day you can keep your shop going. Just be sure that you are selling enough loot and items that you can cover the cost of running the stall.
18. Once you get into Brewing, for the love of everything holy, please do not make the same mistake I did and craft with hard liquor barrels or beer barrels to level. You simply will never have enough Barley to level the skill up at any reasonable speed this way. The “one glass” skills are the only serious way to level Brewing as of right now and you will be wasting your time doing anything else. Also, don't level Brewing, just don't even bother with it till you are end game and have stacks of items for it. It will drain your money and requires tons of Gardening.
19. The Teleportation Skill “Heart's Home” basically takes you to Serbule. You will have always taken a boat to Serbule or used the “Enter the Light” to go to Serbule more often than anywhere else most likely if you have your regular teleport bound to the Casino. Even if you go to Kur and cast it fifty times over and over, it only takes a few dozen boat rides and Enter the Lights to reset it back to Serbule. The way the skill is written, it sounds like it's going to take you to where you have teleported the most, but every use of Enter the Light and Rahu boat trip ticks the counter for Serbule.
20. There are two NPCs that give quests for free loot. One is Pennoc in Serbule, who gives “Entertain Me” quests and the other is Lakrea in Rahu who gives quests for a skill called Holistic Wellness. You will gain levels in the skill as well as items for doing her quests. Both of them may sometimes ask you to do something that you either cannot do or aren't willing to spend the time to do. You can feel free to abandon or cancel their quests, just keep in mind you won't get another quest from them for an hour or so after canceling a quest you just obtained.
21. One important thing I've noticed in this game is sometimes you need to type and repeat the same or similar commands like /particlespam into chat or /invite <playername> over and over. It's not really documented, but you can hold CTRL and press the UP cursor to repeat a previous command/chat. It's particularly helpful if you are chatting with someone and they zone out or exit to switch to an alt for a quick trade and your message fails while they are “offline”. You can just hit CTRL-<UP> to repeat whatever super long message you had just tried to send.

Much of this is compiled mostly from an in-game book by Banos, Seya, Teloch, and Bhelue. I thank them greatly for their work. I did add a few items of my own where applicable to this list as well as edit some of what they added. Also, some of these are repeats from above.

1. The higher your favor with an NPC, the more money they will have for items when they do their weekly reset.
2. High level gear from events (like Kraken appearances in Serbule) is actually mostly pretty worthless, don't take up too much early-game precious NPC inventory thinking that you need to keep it all.
3. Don't focus on min/maxing your gear right away. You will level faster than it is worth the materials to spend. (UE Note: In my experience, crafting anything under level 40 for other players isn't worth it unless you are leveling the crafting skills)
4. Transmutation is still recommended early on if possible to learn (NE section of Ilmari Desert has the hut and NPC, Makara, where you will learn it. Save Rare (Blue/Cyan) or better gear to gain favor with her. (UE Note: You can visit either Anagoge Island or the Serbule Crypts to stock up on this gear to take to Makara. You don't need to do any of this till level 30-40ish though, once you are fully equipped and have a Cargo Gear set and are fully vested in your two combat skills and know and understand the game a bit more)
5. Endurance has +1 inventory skill gains. If you can safely take a fight, let the mobs hit you a bit to increase this causally. Otherwise you might have to do a few sessions where you let bears hit you in Eltibule, Gazluk Mountains, or the Fae Realm to “catch up” your Endurance to where it really should be.
6. Cooking Sausage and Bacon early on are great money makers if you immediately sell them to Fainor after making them. Bacon is even a great early heal ability if you have the Metabolism.
7. At level 10 in Death you get a very important skill, be sure to die to lots of different mobs whenever you enter a new area.
8. Faction focus early game is in getting Joeh and Marna to Soulmates, save up your equipment and skin tons of hides solely for the purpose of gaining favor with these two. When your weekly reset happens you will be so, so, so much happier than if you just tried to sell such things to them instead of using them to gain favor.
9. Civic Pride is underrated if you just go by the wiki stats alone. Light candles after 7pm and snuff lit candles out after 5am. You can do this in Serbule and Hogan's outpost most nights/mornings for easy XP.
10. Having both a meal and snack going during combat is essential to surivability.
11. Item usage goes in this order Craft > Favor > Barter > Sell. . If you can Craft with it, keep it, if you can use it to gain Favor, keep it, if you can't reasonably do either, then Barter or Sell it.
12. You can find where you are storing items using /isearch “<item name>” (without quotes)
13. Basic traveling set that you can make a “Loadout” for contains the following three items: Amulet of the Rugged Traveler (+3 Inventory, +1 Sprint), Ring of Jaunty Traipsing (+1 Sprint), and Windstep Shoes (+2 Sprint, with a requirement of 40 Endurance).
14. Common skills for speed are Psychology and/or Shield. You can get treasure buffs that give you increased speed while Positive Attitude (Psych) or Vigorous Defense (Shield) are on cooldown.
15. It's even recommended to pair these skills into a traveling loadout with something like Battle Chemistry (lvl 39 should be easy to get to once you have a primary skill high enough to level it and will give you decent Sprint abilities and buffs)
16. Also don't forget that if you get Windstep Shoes that already have your Psych or Shield cooldown speed buffs on them, you can then use Shamanic Infusion skills (like Novice's Deer Foot lvl 26) to add yet another Sprint Speed. Shamanic Infusion is a skill like Meditation that levels very quickly but does require a bunch of trophy items from generic mobs.
17. While we are on the the subject, Meditation provides good buffs against the cold. Both Meditation #17 which provides +10 Cold Resistance for a Mycena Mushroom and Orcish Meditation #15 which provide +6 Indirect Cold Mitigation +6 for a Mint Leaf are great for surviving the harsh Mountain areas.
18. Slash commands that tell you what you have done in game are /behaviorreport and /age
19. The Daily is a quest that Qatik gives in the Casino. It will net you either 10k or 15k councils just for doing it and maybe 3-5k worth of items (good for transmuting, augmentation, and favor) and a few casino tokens. The dungeon levels are around the mid-40s range and cycle through the following: Wolf Cave>Dark Chapel>Winter Nexus>Ice Cave (aka Yeti Cave). These are sometimes abbreviated as WC, DC, WN, and Yeti. If you are early in the 40s range, I do not recommend doing a Dark Chapel run as that can slow both you and your team down. +Inventory gear and the Augmentation or Transmutation skills that let you Decompose or Break Down items are a must for DC and highly recommended for the others, too.
20. You can fight the golems in Serbule Keep for a bit of extra cash. Each level gives you a higher monetary reward.
21. Surveying is easier with this link: http://www.defenestration.co/pg/surveying/
22. Mushroom Farming is easier with this link: https://phasepharmer.app/ or this app: https://github.com/dlebansais/PgMoon/releases
23. Brewing is helped by this app: https://gorgonapps.github.io/brew/
24. There is a Poetry Jam at 2pm EDT, 1pm CDT, 12pm MDT, and 11am PDT every Saturday. Avoid using AoE spells and, if possible, get rid of your Ursula curse for the sake of the others participating. You will want to drink alcohol from the kegs that are set up in the back of the inn and pay attention to how your dancing skills switch around on your skill bar as you follow the dancing directions. You can get some massive buffs from this event that will last a long time.
25. Kib the Unkillable in the Casino only holds “Equipment and Ammunition” but that seems to includes things like empty bottles and skulls and bones, so you can have a bit of your Gardening overflow from Tavilak stored on him.
26. Most people who like or love flowers can also be gifted Flower Arrangement items like bouquets. Keep this in mind (especially for Fazzi and Poe which are hard to get Favor with otherwise).
27. You can type “/who near” in any zone to get a list of other players in the same zone at any time. You can also type “/who all” and “/guild who” to see who else is online really quickly. There's also more info in the Social tab on the right side of the screen. (original tip from Herbary in-game)
28. You can “Vendor Lock” inventory folders. If you don't know what these are, don't worry yet. You'll get one after you get a few more skills unlocked or to certain levels. I would highly recommend using these and having at least one for equipment that is “locked” so you can't accidentally sell stuff you know you want to hold onto to a vendor.