We used to have dozens of photo threads. I wonder if they all got archived away when the forums were converted to the new software? Hey ho, not to worry. There's heaps of fun to be had recreating them.

Your question actually wraps three completely different questions into one. How to take photos of fireworks? How to take general scenic photos? How to take photos of people?

These are all different skills and in all honesty you can spend your whole life getting better and better at them. The good news is that you can practice with general scenic photos and people photos before you go on holiday and the skills you develop will be with you forever.

Fireworks are a bit more tricky, but here are a couple of starters ...

http://www.orlandovillas.com/florida...minations.aspx

http://www.orlandovillas.com/florida...-a-tripod.aspx

These are probably a little out of date now and would benefit from a re-vamp, but the general principles I think are still quite sound.

Does the D5100 have a Raw+Jpeg setting? That's one of the first things I usually set. Given how inexpensive storage is these days I can only think of maybe a couple of reasons where it wouldn't make sense to shoot both Raw+Jpeg. You get the benefits that way of having the NEF file and at the same time you have the camera's interpretation in the Jpeg file.