Dodge for all classes: Agility will determine a characters chance to dodge an attack.

Fighting with two weapons/off-hand: Your total damage output when fighting with two weapons should be higher than fighting with one weapon and a shield, but roughly equal to fighting with a two-handed weapon. Off-hand attacks deal 50% of the weapon's designated damage. Therefore, it's wise to always put the best "damage dealer" weapon in the main hand.
Experience

As players become higher level, they will be able to receive experience from a larger range of monsters. At low levels, you may get experience from monsters five levels lower than you, while at level 60 you will gain experience from monsters 12 levels lower. A gray level color indicates that you will not get experience.

Level Cap
The level cap for World of Warcraft is 60.

Language
Each race has a language they speak. Horde players are unable to communicate with Alliance players and vice versa except through emotes.

Skill System
The focus of the skill system is to allow characters the ability to choose secondary skills. As such, attributes are raised automatically when a character levels.

Talents System

Talents give you another way to customize your character and differentiate yourself from other players of the same class. Players can open the talent interface by pressing the "Talents" button, which resides next to the "Spellbook and Abilities" button, or by pressing the "N" default hotkey.

Talents become available at level 10.