Post by Alistair
First off, why the rush? You'd probably do better if you pushed on all the way to 80 without worrying about changing spec. But, if your mind is made up:
As you know, AB gives you a debuff that increases mana cost by 100% and damage by 15% per stack. It stacks up to three times.
This means you're going to tailor your rotation to the health of your mob; you can't spam the same button over and over! Basically, your infinite rotation will be ABx3 + Arcane Missiles, assuming your opponent isn't hitting you. If they are, you can toss in ABarr to wipe the debuff.
However, if your mob doesn't have much health, you won't want to bother stacking AB up to three stacks before dumping it with Abarr or AM. It will take a while to pick up doing it right, but it will help to practice.
As for a spec, http://www.wowhead.com/?talent#ocxVc0ohzxGuMtedz
could be decent. You may want to swap a few points around, put more into improving your mana shield, since you'll be soloing. Also, note that this is NOT a raiding build. You'll still need to respec once you get into raiding or heroics anyway.