I have one, a 9-10 year old small dark gray dwarf "mutt," (he was at a feed store) named Cinder. Here's his set up: he has his own room (no carpet! \o/) filled with toys, hideyholes, beds and hayboxes (2 - one extra large clear rubbermaid container and a smaller kitty litter box). He has a cage, a midwest dog cage that's always open and has another haybox, his water, and more toys attached to the doors.
Here's what he eats: HAY. Our staple is timothy hay. The cuts are important. First cuts (even of timothy) tend not to have as much nutrition, especially if you get them in the pacific northwest, but you can rotate them in (I do) for variety. We got a BIG bale of 2nd cut, so on timothy and keep it in a trash can with a lid. We also get get brom, orchard grass, meadow grass, oat hay for breaks from timothy. These also provide differing levels of fiber and trace minerals. I also feed him alfalfa (sparingly), but NEVER buy a big bale of that. You can be more generous with alfalfa with younger buns, but as they get older, cut it back.
He gets one BIG leafy salad a day. Generally, if you DON'T feed pellets, a rabbit's salad should be the size of their body. There should be at least three leafs and at least three crunchies. The definite majority should be of lettuce (no iceburg) - romaine, red leaf, green leaf, arugula, boston, lamb's lettuce . Feed gassy foods (broccoli, cabbages (napa, chinese, and bok choy), basil, spinach and parsley sparingly (toxins can build up in the last three, and a gassy rabbit can actually die), but you can feed them if the initial moderate amount doesn't produce any symptoms. You have to basically mimic what they could get in the wild to cover nutritional bases.
Cinder gets a fruit salad every/every other day as well. Do you have a toddler bowl? That's about the size of his fruit salad - a lightly filled toddler bowl. Apples (cut out seeds, they're poisonous), pears (no seeds), watermelon (no black ones), banana, mango, papaya (great for preventing hairballs), pitted cherries, plums, etc. There's a lot there
He also gets a handful of alfalfa on days he doesn't get a fruit salad. And he gets herbs/flowers, like calendula, rose petals/hips, chamomile, mint (pineapple mint is a great treat), rosemary, sage, etc
WATER! This is really important. Don't let your bun go without.
Diet IS important, and so is balancing it, just like you would a ferret. That's why so many feed pellets alongside hay and veg, because using hay, leaf/veg/fruit/herb can be work to make sure they're getting what they need, so whatever route you take, be comfortable in it (and no-pellet diets can be done, and done successfully. Cinder, from the time we took him home, has NEVER touched a pellet and he's not only alive, but happy and healthy).
It's important that a rabbit's day is spent nibbling. During stress and sicknesses the key thing is to keep your bun eating. Rabbits' gastrointestinal tract can stop (GI stasis). It's painful and it can kill them, and trying to get it jump started is also painful and tedious. My Poppy died from it, and it was terrible.
Another reason why it's important is because it's their major form of stimulation - the size, shape and smell of the food all serves as entertainment for them (that's why you can cut things differently, serve at different temperatures, etc, as long as you never feed cold or frozen to your bun - that can actually harm them. Feed room temp or cool), and rotate foods frequently.
Introduce one thing at a time, though. Feed it at one meal, check poo. If there's loose/liquid stool, cut it from the diet and move on to something else. If there's none of that, keep it in and add a new food. Feed the two, check poo, decide, so on and on until your done. If you stop feeding something for a long time, when you go to reintroduce it, put a little bit in the salad and slowly increase the amount over a few meals. Rabbit bodies have to get the right enzymes going and if they're given something they don't have the enzymes to break down, that'll cause issues.
Spay/neuter
That's important! More for the males' temperament and for the females' health and lifespan. It's also important that you find a good vet who can do it. I took my Poppy to a well known vet clinic with an awesome rep, so I thought I was safe. However, the *vet* butchered her and left her with a short lifespan filled with medication and pain, so. Be absolutely careful about the individual person that's going to do the surgery (especially spays).
They're intelligent, and they have a very specific hierarchy, and they'll try putting you at the bottom, and you can offend them really easily (it's hilarious).
There's a ton more info out there, and it's great your doing the research! Rabbits are unique, and they bond very strongly to other buns and to YOU, and they will give you a lot of great, great memories. I've cherished every single day with my buns, and don't regret being owned by them.
(ugh, sorry so long and probably for a crap load of typos :C )