angieluv has pointed you in a good direction!
I guess a good diet is based on YOUR rabbit and what you "use" that rabbit for ie. a breeding or lactating female will need more clacium, a young rabbit needs extra calcium, a show rabbit needs to be kept in good coat condition etc. My rabbit (half dustbin half lionhead) eats on a daily basis 1/8 cup of pellets and free feeding hay (as many different types of grass hay as possible with alfalfa mixed in every now and again) then at least every other day at the moment(depends on what I can get) he gets romaine lettuce, a small peice of carrot, fresh grass, coriander/cilantro, a small peice of celery or cucumber and usually a leaf of any other lettuce excluding iceberg and then I change differnt things around like he gets a peice of fruit every weekend, parsley every few days, kale 2-3 times per week, fresh clover, chick weed, dried nettle/agrimony/yarrow and different things like that, he seems healthy and I have never had a problem considering I have been told he has a sensitive stomach and will likely have slowing of the gut a few times.