I just finished leveling as fire and it really perks up at around level 60. I used the leveling guide on www.wow.com as kind of a road map to talents. Here's my mage for what it's worth. For now I probably have too much spirit on my gear (but it does go to crit, so not a total waste), but I'm taking what drops I can get until I get more picky in ICC this week.
I know the rotation I use now is Combustion, Living Bomb (keep it up on target), Scorch (refresh as needed), spam Fireball until Empowered by Fire procs and hit Pyroblast.