Depends on your budget, type of camera and space available and how much reuse you might get out of the lighting equipment.
Low end (About $30)
Backdrop is an interesting wall, doorway etc, If you want a flat backdrop you and use a sheet and clips or blue masking tape.
Lights: Pick up some inexpensive clamp on lights like this:
http://www.lowes.com/lowes/lkn?action=p ... lpage=none Pick up a couple of bulbs for ease get one bulb 2x the lumens of the other (like a 200w and a 100w)
Be careful these will be hot and you don't want to burn anyone.
Next step up is inexpensive continuous lights.. These are fine for casual use something like
http://www.amazon.com/Cool-Flo-Fluoresc ... B001COVC8M With kids you can get away with the harsh lights of number 1 but with adults softening the lights with modifiers, like umbrellas and soft boxes, works better.
If you have a DSLR you can look into strobes
As for setups the following has some basic stuff...
http://alzodigital.com/photo_guide/continuous_usage.htm