Besides a basic diet of greens, salt blocks, some root veggies and grains (sparingly), and a chunk of tree limb with bark still on it for chewing and keeping their teeth nibbled down to length. Some dry grass/hay should be feed also, alfalfa wafers work well.
If you lay wire netting down on the grown you can allow them to run in a fenced yard. The netting is necessary or they will burrow out. Small indivivual shelters should be provided if they run, these will double as kindling dens. If penned you should provide a cage about 30X36 inches per adult rabbit.
A tin can or a ball gives them something to play with, they will push it around with their noses.