Ok I'll start you off. You see. Like a wow guy based off your posts so I'll be referencing similar things from wow.
Leveling: this is an alpha stage game that's one thing you must understand. So things like public quests, and dungeons are not get available to help level from a PVE standpoint. The best current way to go about leveling in my opinion is to play yourself through t1 to get a basic understanding of your class and its mechanic. Basic information on that can be found here.
http://warhammeronline.wikia.com/wiki/W ... nline_Wiki
You will also notice that you have 2 lvl bars. The second (purple) one is your renown rank. Its your PvP rank for all intensive purposes. This is raised only by doing PvP, either Scenarios (which are just like WoW battlegrounds for the most part), or RvR, world fighting in the designated "lakes"
Crafting: In warhammer there are 4 gathering skills and 2 crafting skills a link with more info is here
http://warhammeronline.wikia.com/wiki/Craft for a first time player I would grab cultivating and apothecary as it is the most diverse and useful to have. There are two addons that are a must for these in my opinion and that is MGremix (miracle grow remix) and motion. Both make these professions much easier to do. Search in the forum for the addon pack someone made of all the games addons and you will be able to download them all. (100s)
The Holy trinty in War: the big difference in Wars holy Trinity (tank, dps, healer) and WoWs is the way tanks are used. In wow tanks were just flag carriers. Here they are essential to every group. They all have a baseline ability called Guard which allows them to absorb 50% of the damage that is being down to thier guarded target as long as they are withing range. They also tend to have most of the good CC in the game.
Immunities: in wow when you stunned someone if you did a KD right after it you got depreciating returns. Here on war once hard CC (KD, stagger, disarm, silence) is used on someone they are immune to that form of CC for a given time. This is an immunity timer and it will show up on your targets buffs/debuffs. The same applies for soft CC(punt, root). An add-on to download that helps keep track of these is buffhead 2. You can configure it to show just immunities or a range of other things as well. It's very useful.
AP regen vs mana pool: your going to notice a big difference here. All classes run on AP.
Specing: There are two specs for each class. These can be done from lvl 11 onward, you get a point every other level for a while. Here is a link to the builder. Mastery and Renown Spec are what you are looking for
http://waronlinebuilder.org/
Some class comparrsions for you below:
Hunter=Shadow warrior, squigg herder, engi
Mage= bright wizard/ Sorc
Warlock= magus
Warrior= kotbs
Deathknight= chosen/ marauder
Priest= runepriest/ zealot
Shaman= Archmage/Shaman
Rouge=Witch hunter/ Witch elf
Paladin: Warrior priest/Disciple of Khain or in tank mode ironbreaker/ Blackguard
Monk: Swordmaster/ Black Orc
).