There are literally hundreds of wireless shutter release available both in ebay and in the store or just get the Nikon original one which I don't think would cost too much... and all of them worked well, depending on what features you want... alternatively, you can get the wired remote control which is going off at a very very cheap price...
As to what tip to shoot firework...
1) tripod
2) remote control - wired or wireless (personally I am using a wired one)
3) black card (optional - personally I have not use that before)
4) Your camera
5) lens (normally UWA lens is prefered, but not all the time, depending on what you want to shoot, what is your framing and composition, I have read that you can achieve great firework shots using tele lens too.)
6) Lots of water and/or beer (to quench your thirst)
7) Food (I would expect yourself to get to the location early to chop a place for yourself, so food is important)
As to how to shoot firework, you can read up alot in the internet. For me, I normally choose a spot that I wanted, frame my photo, then thats it. When the firework started, I press my trigger hold (depending on the firework shots) for 1 to 3 or 4sec. For the red firework, I try not to go pass 3sec for it will overexpose my shots.
And thats it.