Use a bow for lower levels as a mage - you'll need to be over level 10 before you can fight by magic alone. But it is a very powerful class once you reach higher levels.
Some general advice (which you can find by following Raze's links):
- Concentrate on Int, followed by Spirit - I kept my Spirit at 50% of my int as it was better to kill fast as a weak mage, rather than having stamina for a long battle.
- +Magic damage enchants are the best enchants you can have - dual wield so you can eventually cast +100 magic damage on both weapons, and keep an eye out for jewellery with 'built in' +magic damage enchants.
- Magic Missile is probably the most powerful spell in the game as when you max it out, you will get 7 missiles per cast, and your +magic damage bonuses are added to each missile. So combine this with +100 magic damage on each weapon, and you'll be getting +1,400 damage per cast.
- I'd also recommend fireball (area effect, and moves faster tham magic missile, so it can hit fast moving flying targets that magic missile generally misses). Firewall is useful for when the bad guys get too close, and Destruction (followed by Way of the Battle Mage) is a great sink for spare skill points as any increase in damage is highly desirable.
Anyway, check out Raze's links for more advice from me and others (I always play a mage..).