Really it depends on how magic works in your written world, but here are some (from games, texts, and other places)
Alteration
Evocation
Mysticism
Illusion
Thaumatergy
Chronomancy
Geomancy
Sorcery
Conjuration
Restoration
Divination
There is also the more Oriental/elemental approach. Magic is a way to manipulate and control (or even create) different aspects of the elements (traditionall fire, earth, air, and water, sometimes with others added).