A DSLR is going to be the best bet for varied lighting because of reduced noise at higher ISO levels when compared to a point and shoot, as well as better control over shutter and aperture. However, there are some pretty decent point and shoot cameras out there that can be had for very inexpensive prices. It all depends on what you want to spend and if you want to get more serious.
Digital Camera Reviews and News: Digital Photography Review: Forums, Glossary, FAQ is a good resource for in-depth camera reviews with example and comparison shots.
I also agree that you can't go wrong with a D40. It is easy to use, takes great pictures, and the included kit lens is suprisingly good. I paid around $500, but it can likely be found for less these days.