Shooting fireworks is actually quite simple. I remember when I did so back in the film days and I was so surprised when the images came back actually showing fireworks.
My setup is basically, f/8, bulb setting with trigger cable and tripod (of course). The lens is whatever I choose. This new years eve I had been playing with my macro lens and I didn’t change it so I ended up with 100mm on an APS-C sensor. It works ok since our house is quite elevated and I wanted to shoot the fireworks that came from the islands around us. It was quite windy (when isn’t it) and there was some mist in the air. I got one or two shots that I’m fairly ok with though.