Valid Races: Gnomes, Humans, Draenei, Undead, Trolls and Blood Elves

The Mage is the typical spell caster. They are very dangerous at high levels, but as Blizzard so eloquently states on their class page, one of the challenges is keeping them alive. Once an enemy gets to you, they can kill you very quickly. A mage is always in demand in parties though so there should not be too many issues staying alive as long as you have a tank or two in the party as well.

Links to information on other WoW sites

Blizzard WoW site - The official Blizzard WoW Mage information page.
Mage Articles - Article submissions from players about Mages on "The Knights who say... Ni!" site.
Mage Character guide - Starting levels and brief talent descriptions at the wowvault.ign.com site.
Graffe’s Wizard Compilation - A site devoted to the Mage class .