I am also a newbie. While browsing the CS forum, I collected some notes on taking frieworks. Sharing it below.
I go into manual (M) mode and use bulb shutter setting for the fireworks. Use ISO 100 and F/8-F/16 (do some test shots of the first few bursts and adjust the aperture accordingly
Use a tripod. You can't handhold the camera for a time exposure, even if you're using an IS lens.
Use ISO 100 or lower. Fireworks are bright and the lower the ISO setting, the lower the image noise.
Stop down to around f8, maybe f11. This will give you the sharpest images and allow a long exposure.
Prefocus the lens and switch to manual focus.
Try shutter speeds from 2s to 8s. The longer the exposure, the longer the trails will be.
Open the shutter while the firework is on it's way up, not when the shell explodes.
A remote release will be useful. Use one if you have one.
In bulb shutter mode, you press the remote button to open the shutter, the seconds starts counting.
Yes, Bulb shutter is right after the 30 seconds setting for shutter speed.
Haha.. I've not heard of anyone who take photos of fireworks (long exposure shots of more than 10secs), handheld..
You need a sturdy tripod. There will be many people and it will be extremely packed there.