so i'd like to add a light (or two) to the ceiling of the cargo area to illuminate in the following situations:
1. rear hatch is opened (is this possible?)
2. switch is flipped.

i'd also like to add additional reverse lights (nothing too powerful, keeping it legal) to illuminate in the following situations (using a switch):
1. Off
2. On with reverse lights

what are the basics that i will need to know about before i start on this (relays, switches, etc)? i'm a newbie at this modding gig, so any and all (good) advise is greatly appreciated.

thanks,
DM