Easy peasy lemon squeezy. Start Flame trap/Ice Nova, then switch to Searing Bond/Flameblast after you buy a +1 to fire gems 1h Mace (Saw this leveling technique from Ziggy...maybe?) They run around 1-5 Alterations, maybe a Chaos if it has good spell damage.
Then ride that to the 50's, it's pretty simple. This build will make you incredibly tanky while leveling. I usually had blues with hp, and a couple rares with resistance and I was fine.