(taken from warhammer wikipedia)
So every career has some sort of mirror to them. Iron Breaker:Black Guard, Witch Hunter:Witch Elf, Marauder:White Lion
However each carrer also has their own unique aspects to them. For example:
Iron Breaker specialty is their Oath; in which they gain per hit landed on him or his oath friend.
Black Guard however uses Hate, in which they gain every time they hit someone.

In this way; no two classes are the same providing a more versitile world of classes that you can join into.
I'm not going in depth with the classes; as that wouldn't be reviewing the game but giving my own personal input on the classes; So onward we move.
Skills are similar to WoW talents. You have your Core skills, your general skills, and then your Tactics (which can be related to Talents). You gain one tactic point every odd level after 10 and it can be placed in either of three skills in every class (each tree focusing on something different, Offense, defense, Support).
Along with the active skills; we also have Tactic skills which are passive abilities you can equip. You may use one tactic at first, and gain one tactic slot every 10 levels.
Tactic passive.. what does that mean. Well; things such as "Monsters will do 25% less damage to you but you deal 10% less damage" and so forth. Their passive advantages that you don't need to activate to use; not to be mistaken by buffs.
Yeah; the terms do mix alot.
Other than the core skills and whatnot; you are also offered Morale Skills. You gain morale per attack your group does against people. It's pretty much your limit break from final fantasy, your musou from dynasty warriors. A special attack (no it's not rigged, but it is far superior to your regular skills). This skill can give you the upper hand in a fight however it has a long cooldown.

Alright; so enough of the careers and skills right? Gameplay! RAHH!! What makes War different from any other game?! What makes it different from WoW that would steal it's community?!?

Warhammer Gold has the following to do:
Questing. Killing. Public Quests(explained later), Scenerios(Battleground equivilant), Keep wars, territory war.
Questing and killing, their your regular PVE aspect of the game.
Public Quests were introduced in Warhammer gold and are quite fun. You gain influence per public quest you complete in which you can gain special items from. Public quests are story-arc quests that occur every 5 minutes after the previous has been completed. Anyone can join in on the quest, you just have to walk into the quest area. don't even have to be in a party.
Once the quest is completed. you are entitled to a grab bag; in which is determined by how much you contributed to the group that public quest and a lucky roll(which is totally bullshit because top contributors can get knocked down to the bottom because of luck) (this is also promised to be fixed later by Mythic)
There are gold Bags, blue Bags, Green Bags, giving better items at gold bags and crappy items on the green bags. This has no relation to the influence prize I spoke earlier; this is just a reward for finishing the public quest.
The influence reward is claimed at a rally master. Prizes varie in quality.