OK Heres the deal on shooting fireworks. Start by making a short (2 to 3 length) light tight tube to fit over your lens (I would use the longest lens I have available). This can be made from black poster board and gaffers tape (gaffers tape is basically black duct tape). The tube should slide over your lens with just a very slight amount of friction. Now find a place to watch the fireworks that does not have much ambient light in the area (the darker the better). Mount your camera on a tripod and if you have one attach the cable release. Set your camera to f-8 and focus on infinity. Set the shutter speed to bulb (this means that as long as the shutter release is pressed the shutter stays open). Now zero in on the area where the majority of the fireworks will explode. Place your handy dandy tube over the lens and press the shutter release. Do not let go. Each time you see a burst coming that you want to record, remove the tube and then replace it after the burst. My suggestion is to build up three to five bursts for each exposure then let the shutter close and go to the next frame or image. While it is nearly impossible to predict exactly what you will have, the results are usually pleasing.