Got a budget in mind? Do you already have a lighting setup?
My "starting point" setup generally is one umbrella as a key light (roughly 45 degrees to the subject). I'll set that to f11 or so. Then a fill light more or less opposite of the key light, set to maybe f5.6 or f8. There's no limit to how much experimenting you can do by varying the lighting angles and lighting ratios of a basic two-light setup.
If you have a third light, make that a hair light...up and behind the subject.
If you have a fourth light, put it behind the subjects and use it to throw light on the background.
If you are on a really tight budget, you can still do great stuff with a single light. Adding a reflector for the fill light will improve your control/results.
Good luck and have fun!