Yup, I have played just about every MMO out there and I'm not particularly great at any of them. Here are the things I learned about this game which, under normal circumstances, prevent me dying every fifteen seconds. They won't make you uber, but they may make you less frustrated.
1.
Pay attention. Sometimes what the quest giver says is actually meaningful. Even in cases where it won't help you with the quest, it will help you figure out who you can trust, who's gonna be a problem five quests from now, etc. If you remember who's pissed off at you at the end of Auridon you'll be less surprised by what he does in Grahtwood.
2. Red sparks coming from your enemy during a fight means use your interrupt key. (If you are a klutz like me you will not be able to get the mouse-buttons default interrupt to work well. Map it to a keyboard key instead.). White sparks during a fight means press AND HOLD your block key - you have to hold it down until he actually bounces off you. Red areas on the ground mean GET OUT OF THOSE QUICKLY. Double-press one of your movement keys to roll out fast. If the enemy has a gold outline of a shield in front of him, he's blocking YOU - don't hit him with your normal weapon attack or YOU'LL bounce off and be stunned. Short weapon attacks (press left and let go) are usually not worth it unless you're trying to finish off a nearly-dead enemy fast. Long (heavy) attacks (HOLD left button down until it releases/swings by itself) are usually the way to go.
3. "Read" all the books/scrolls/notes you find, especially ones which are glowing, and especially especially ones which are glowing blue. I put "read" in quotes because you don't actually have to stop and absorb the lore in them (although it's often interesting), just open then and close them again - some of them will advance some of your skills, and you want that, believe me. The blue ones also advance your Mages' Guild score. The various notes and such usually have pertinent information about the place or situation you're in. Basically, if they made something glow, they want you to read it, so read it.
4. Join the Mages' Guild, Fighters' Guild, and Undaunted immediately. There is no penalty for joining all three. You may never use the skill lines they open - you may never advance them - but why not keep your options open?
5. Most stages in Mages' Guild, Fighters' Guild, and main quest lines (Prophet and Friends) are solo-only. Yes, this sucks, but don't waste time screaming about it. Wait until you're a couple of levels over the stated levels for these quests, go onto the forums or the web to find the secrets of a particular fight, and persevere. (How do you know the level of the quest? Try the quest listing on the J screen.)
6. Learn to use the compass/map markings and you will be happy. In general, anything which is black is a quest or area you haven't done/finished yet (or a quest you don't currently have selected). When you finish them, they turn white.
7. The torch markers are dungeon areas. Six of them in any given inland zone are little "delves," very simple - these will be a loop of passage with a boss and a skyshard. Kill the boss to "complete" them. One of them is a sort of mini-dungeon with a lot more mobs, multiple bosses, and some achievements ... and a skyshard. You usually will want help in those, but they're soloable with care. Its map symbol will be a torch with a plus sign. The location with the two crossed torches is the zone's big group dungeon. Find a party for that.
8. The markers that look like crossed tools on fire are special crafting areas out in the wild. You can craft normally there, or, in the right circumstances, craft special set items.
9. The "eye" markers are notable locations (Points of Interest). They're usually not all that interesting but you get an achievement for finding all of them in a zone.
10. Do not neglect finding skyshards. You want those skill points. Look behind buildings. Do not neglect finding wayshrines. Wayshrine-to-wayshrine transport is free. Wilderness-to-wayshrine recall costs money.
11. Stay very close to level on quests if you can. Experience from them drops off quickly when you get too high level for them.
12. Find your crowd-control (CC) skill(s) and get them out early. If you are a DK, get Stone Fist and use it. The enemy cannot hurt you if they're on their ass. If you're a sorc who hasn't gotten your big zaps yet, get a fire staff and the first Destruction Staff skill and use it for knockdown.
13. In general skills advance by using them, armor lines advance by taking damage on armor of that type, etc - but things also can advance JUST by being on your skillbar. So if you're trying to improve a skill you're not currently using, put it on your skillbar anyway and let it ride a while.
14. You can't do all the crafts with a single character effectively, no matter what anyone here tells you. Make some hard choices. Apart from that, crafting is surprisingly useful in this game and it's a perfectly fine idea just to specialize in making armor and weapons for yourself and nothing else. (The only problem is that the main way you skill up crafts is to deconstruct items of that type, and it can't be your own - well, it can, but you get next to zero exp for it. So save your unused armor/weapon loot to deconstruct and/or research! Or get some from your friends!)
15. Apropos of that, pick your weapon style(s) - no more than two - and your armor style (1) and STICK WITH IT. Remember that in this game two-hand style doesn't mean staves and it doesn't mean bows, and remember there are two kinds of staves.
16. Due to a stupid decision at the end of beta, you are now taken to the first "inland" or "real" zone for your faction as soon as you finish the Wailing Prison. Go find the person somewhere on the docks of that town that will take you back to the "starter islands" and work through the quest progression there normally. Otherwise you will have real trouble staying on quest level later, and will also miss a lot of opportunities to level skills, plus needed training, plus quest lore, etc etc. If you can't find the NPC to take you back to Kenarthi's Roost/Stros M'Kai/Bleakrock, ask.
17. You're probably not uber enough to do an anchor alone, but they're worth doing. Wait and see if others show up. They usually will. (The "wait for someone else to show up" also applies well to hard bosses in general.)
18. There is such a thing as exploration exp, but you have to get close enough to something that the game says you've "discovered" it. This includes delves, boss areas (skull/crossbones icons), quest chain areas, basically anything with a map symbol. Do this. In addition, "discovering" something will make its map icon permanent so it doesn't disappear once you move away from it.
19. The stones with names of constellations (yes, in Elder Scrolls those are constellations) (The Lady, The Lover, etc) are Mundus Stones and they give permanent buffs - permanent, until you replace them with one from a different Mundus Stone. Your character screen will show you your current buffs/debuffs at the bottom - hover your mouse over them for an explanation.
20. If you've never played an Elder Scrolls game, you'll quickly find there's a whole lot of terminology the game assumes you know. Too much for this space. I wrote about a fair chunk of it
here.
I have just told you more than I know.