The golden rule when you buy a rabbit is to make sure that you have been given change over feed so that you can gradually change your rabbits diet over a period of 10 days. A sudden change in diet will make your rabbit very poorly.
1) Nutritional Needs
A wild rabbit will have an endless supply of wild plants and grasses and they instinctively avoid poisonous plants. In the modern world it is not viable for the keeper to scour the hedgerows looking for their dinner for them so a more modern approach is taken.
Pellets are used instead, which are a compound feed with all the correct nutrients and vitamins for your pet. Superior mixes are also available and can include dried carrot, peas, cabbage and molasses. Molasses in very small quantities can be a good tonic just be careful not to overdo it. All pelleted and mix feed should be stored away from mice in chew proof containers.
2) How Much To Feed
A dwarf breed needs 2oz of concentrated feed per day and a large breed needs 4oz per day. Finding a cup which holds this amount will save you having to weigh it each day.