If you are looking for the FASTEST WAY to reach level cap with your mage the World of Warcraft, this KillerGuides' WoW Mage Guide is what you must have. It's by far the most complete mage guide I have seen.
The mage focuses on DPS, crowd control, and burst damage although after patch 5.4 goes live it is likely that the mage burst potential will be reduced. Mages use one-handed swords, wands, daggers, and staves. Although this class can only use cloth armor the Mage has buffs to increase their defense.
In PVP the Mage is devastating. Polymorph, Couterspell, and Frost Nova are powerful crowd control spells that will many times decide the arena match or battleground. If you think Frost Nova is no big deal then you are not playing a warrior and you don't queue for Strand of the Ancients.