A racquet is one of those things you just have to try. As a beginner you're probably going to want a bigger racquet head, like a mid-plus(offers more forgiveness with off center hits, and usually transfers more power to the ball) with a lower string tension(offers more pop, so you can work on swing mechanics, instead of over swinging to give the ball some pace), but this is all something you should try out at a local tennis shop. Or even if a local sports store(Dick's Sporting Goods, MC Sports, etc.) offers demo racquets, always take advantage of that and try them out.
I personally like Wilson racquets, but everyone has their own personal preference, and sometimes you might like a racquet from a different brand than what you're used to.
This post was edited by BlackKnightsOfFistingPower on Jan 26 2011 10:57pm