http://www.unofficialwowguide.com/blog/world-of-warcraft/world-of-warcraft-whats-the-best-mage-build
Mages do amazing damage, and have some of the best crowd control in the game. Mages do damage with direct spells, they can unleash huge damage in a little time and they have effective area of effect spells that slow and damage every enemy in a certain radius. Mages are depended upon to cause major damage in groups as well as give out intellect buffs to all casters, polymorph key targets and set a nice table by way of conjuring a Table of Refreshments providing food to regenerated mana and health.