Feeding your pet rabbit should be easy and enjoyable. Remember that rabbits are herbivores who survive on grasses in the wild. Pet rabbits get a bit more variety than wild rabbits, but the basic nutrition should stay the same.
The most important part of a rabbit's diet is timothy hay. Your rabbit should never run out of hay. Some people even use hay as bedding so that they can fill the whole bottom of the cage with the food product. The fiber of timothy hay is critical for proper digestion.
The second most important food for a pet rabbit is leafy greens. Your bunny can eat kale, spinach, romaine lettuce, cilantro, parsley, carrot tops, collard greens, and more! The rabbit should get at least two large salad bowls full of greens each day. You can buy whatever greens are on sale, and make sure to rotate the greens every few weeks because different vegetables provide different nutrients.
The least important part of the diet is timothy hay pellets (bunny food). A pet rabbit doesn't need any more than 1/4 cup of pellets each day, since the hay and greens provide all the nutrition he or she would need.
You can give your bunny healthy snacks such as carrots, apple slices, and bell peppers.
Foods to avoid include cabbage/broccoli/cauliflower which cause gas production and bloating in rabbits, banana/citrus/berries which can cause diarrhea due to high sugar content, and cereal/nuts/seeds/crackers which are difficult for rabbits to digest.
Please check with an exotic pet veterinarian if you have any other questions about rabbit diet!