The digital Rebel has all the settings you need to get GREAT fireworks shots. BUT...you can't expect good results in the auto setting. The article the previous poster pointed to is an excellent primer, but I would differ with regard to one thing. The landscape setting that is suggested will set the camera to infinity focus which is what you want. But it will also bump up the ISO which is something you don't want. Instead, I recommend you try the following settings:
1. set you camera to M (manual) mode
2. set the aperture to f/16, ISO 100 and a shutter speed of 2 seconds (you set this one time and you're set for the whole fireworks show) (You can experiment with other settings, but these will generally produce some good captures of fireworks).
3. set your lens to manual focus and then focus to infinity (or sometimes I just focus on an object...like the castle...that will be in the foreground of my photos).
4. Tripod, Tripod, Tripod...you must use a Tripod. With a long exposure of 2 seconds, you'll get nothing you can use if you handhold your camera.
I know that the thought of setting up the camera in M mode can seem daunting. But just practice a couple of times before you leave. You'll find it's really quite easy, and it greatly increases the types of situations you can shoot in.
JimmieD
