Settings For Fireworks

My Recommended Settings For Photographing Fireworks Are:

Tripod*
Manual mode
ISO - 100 or less
Shutter - Bulb Mode (or approx 3 sec)
Aperture - f/11-13
WB - Daylight
Use Remote Control/Remote Shutter Release/2sec Timer to avoid Camera Shake

I always use wider lens (focal length less than 50mm). Trust me its better to have a wider lens.

* - Tripod is the only thing constant in the setup and without which not a single picture would be a keeper.