How much do you plan on using it? What more do you plan to shoot besides your 6 month old child? Are you hoping to devote your life to this hobby, or are you just wanting a "big camera" that takes "really nice pictures?" Because the D7000 kit listed above is an amazing tool, but it's going to push you pretty close to the end of your budget. Now, don't forget that with a new camera, you're going to want and need some other accessories - a bag, memory cards, even software. Lens filters, tripods, different straps, flash, new glass...
If you just want to take really nice snap shots of your child, I'd suggest something along the lines of the D3100. It's cheap, and you can find them used pretty easily. You can afford to get a decent lens, and you're not set too far back in your budget.
The best recommendation, honestly, is walk into a photo store and hold some in your hands. Snap a few frames in store. The difference in size between the D7000 and D5100/D3100 isn't huge, but it's very noticeable. Go try some out.