I have the Digital Rebel too ... you'll love it ...
For lenses, my absolute favorite is my Canon 100mm, f/2 ... it is amazingly fast and sharp. Plus with f/2 you can really get neat DOF on your shots. It is more of a portrait lens, but I use it for some outdoor stuff too.
Other than that, go for fixed lenses over zooms when practical ... I have a 24mm, f/1.8 and a 50mm, f/1.8 fixed lenses that work very well. The 24mm is still not as wide of an angle as I would like for digital (which has a smaller imaging area than 35mm film, thus having the affect of increasing the magnification in your photos) ... my next lens will probably be the Tamron SP AF17-35mm Di LD, which was designed with the digital size limitations in mind. Got a great review in this month's Shutterbug, and it is around $450. For chasing I use a Sigma 24-70mm zoom quite a bit that turns out nicely for the most part.