Hey there! I am a very active sports photographer myself so hopefully I can help you out as well. Previous poster is correct, Optical Zoom is way better than Digital Zoom so you want to get the most optical zoom you can. In your price range, you should be able to get about a 10 optical zoom with additional digital zoom beyond that.
When I was shopping for a digital camera, I also wanted to be able to take a series of shots (action shots) so having a "burst option" was important to me. I am able to take 6 shots in a row by holding the button down. Not sure if that is important to you or not, but it might be if you are taking sports photos.
As far as other features that are available, my camera (Fuji CoolPix) for instance, can shoot video as well as still pictures, have the option of shooting in Black and White as well as Color, determine number of megapixels to shoot in (1, 2, 3 or 6), and I can unload the pictures directly from the camera into the computer.
I would take a look at
www.bhphotovideo.com - they usually have very competitive prices.
Also I highly recommend checking out
www.dpreview.com. It has reviews of nearly every camera out there and will compare them for you as well as forums to ask questions.....