I've experimented somewhat with this. You can tether your camera to the computer and people can actually see the photo right there on the screen! It's pretty fun. Then once they choose their photo, they can hit print and have
it right there.
As far as the lighting kit, you would have to figure out the proper lighting and get that set up before, and that may get a little time consuming before the wedding. I wouldn't worry so much about that, but maybe have just some regular
lights above and shoot on auto. I wouldn't get in to the P mode for this, and definitely auto focus.
I also shoot with a d5000, so if I get my camera set back up in that mode, I could probably help some.