Well ... as I posted above, being a prior D2 fanatic and after a week of PoE, I can say I'm into it.
First char was witch/elementalist. I went with an incinerate/FS build and currently sitting @ lvl 74 in A4 Merc. I haven't really gotten to understanding a few things yet:
1) Crafting. This seems like the way to go for ridiculous items since you can re-roll/re-socket/customize items a lot (unlike D2). There's so many orbs that have their own crafting ability, and I need to understand more of what a typical combination is ... starting with a white item. The problem there is: (see #3 below).
2) Currency/Worth of items. It's cool being new to a game where you're still learning, but this is an area that is a must. I'm using certain guides to see what items they're using, etc... but knowing what makes an item worth something is necessary for trading and obviously improving your char. The obvious ones are max life and resist, but it seems there's a lot to learn in this area....
3) Learning the levels of all the armor/weaps. Holy hell are there a bunch. This was second nature in D2, but I also spent a hell of a lot more time on that game. I guess this will just come with time. I don't want to craft a lower quality item when/if there's better out there. AFAIK, Vaal items are pretty high? I also see everyone pick up white leather belts ... which is weird, because I know there's better/higher quality belts out there. What am I missing?
4) Spells/Tree. IT'S SO BIG! Again ... time.
I want to get all this stuff out of the way (now) before the next league starts. That way I'm ready to roll whenever that time comes.
So, who wants to play later?
1) Crafting is in a poor state atm. Besides jewelers (changes sockets), fusings (changes links), and the alteration / chaos spamming on item, nothing else is really worth using. Crafting isn't something you should embark on until way later in the game. The end game crafting (using exalted orbs) generally has no returns. An exalted orb is worth far more in currency than what you're likely to craft with it.
2) It takes a bit of a feel. Poe.trade is also a good place to look up around the stats of your items to find if they are worth something. This is a video by one of the top streamers about price checking items, and it can help give you a general idea of worth as well.
https://www.youtube.com/watch?v=YDtukG7HAgw When it comes to gear, defense and then damage is generally the order of important.
3) White leather belts are in a special place because there is a very rare belt you can chance orb in a certain area. You're probably better off not bothering with worry about this unless you want to scrounge a little currency (white leather belts are like 6 to 1 chaos if you want to sell them). As far as other items, there are a few top end items you'd want to be looking at to craft, and even then, the item level has a lot to do with it. exilemods.com lists the possible suffixes and prefixes aavailable on item at which iLvl.
4) Skill gems are a lot about what feels good for you. While, some are way better than others, playing builds that aren't fun (bladefall poison trap...) just isn't fun. If you find something you like, go with it. The tree is about a balance between what key stones you need and what is the most efficient path to maximize your damage and defense on the way. It takes some getting used to, but you'll get there with time. There are quite a few build planners out there that will help you. Most builds should be "finished" at around level 85. Also, almost always help Oak in Normal. Unless you're going for something that isn't life based.
Also, melee is in a fairly poor state atm. Namelocking means only a few skills are truly viable options to not feel extra clunky and those aren't the funnest. It's novel at first to use EQ and explode everything, but grinding to 100 with this is going to be tough.