Lots of excellent advice on selecting the appropriate camera - let me throw in a few bits on making the purchase:

The internet makes it really easy to search for the lowest price on a given item, but you shouldn't always choose that vendor. Check out www.resellerratings.com for info on various mail order outfits. Note both the average rating AND the number of ratings when making a choice. It's a life-saver for computer and photo equipment.