How to Photograph Fireworks

1. Use a tripod
2. Turn your flash off, no need for that here. 
3. Use a zoom lens if you can (until the fireworks start, you won’t know exactly where in the sky the fireworks will appear).
4. Shoot in manual mode.  You don't want the camera to take control!
5. Use a low ISO like 100 or 200
6. Set shutter speed to bulb.  This means you control how long the shutter stays open
7. Aperture should be between f/8 and f/16
8. Lens should be focused near infinity.  If your lens won't focus, set it manually.  
9. Hold the shutter open for about the amount of time you see the fireworks in the sky you are capturing, somewhere between 1-15 seconds. Experiment with this a bit to see what you like.
10. The shot below was captured in one second.  With longer shutter speeds and large bursts of fireworks, the results can be quite stunning.  
11. Have Fun!