Trying to find a good mage leveling build can be difficult. Many of the ones available online don't take into account changes made in patches. Either that or they were made before the Wrath of the Lich King came out. It took a while but I was able to locate a good mage leveling build that's up to date. It's helped me speed up my WoW mage leveling without having to resort to any power leveling help.

A good Wow Mage Leveling spec is one that allows the mage to do a lot of damage in a small amount of time, without exhausting the mana supply. I've found that focusing on the fire tree brings the best bang for the buck and can help a mage level faster than trying to balance spells between the three trees. Frost and arcane are good spell trees depending on the type of mage that is being played. A fast leveling mage build needs to focus on the fire tree more than the other three to be effective.

WoW Mage Leveling Guide