For $600 maybe get a Nikon D40 and some accessories, like a tripod, bag, possibly an extra lens. Cause sooner or later your gonna end up buying those things so why not get them right at the beginning. Plus since your a beginner a D40 or D60 will help you to learn without confusing the hell outta ya and they still takes awesome pics.

You can get a new D40 for about $450 or a refurbished one for $375. Or if you want to spend a little more then that go with a D60. Do some research, read reviews, and make sure you know what you want before you buy.

I shoot with a D40 w/kit, the 55-200 VR, a 50mm prime, and a few flashes.