The House Rabbit Society is probably the best resource for rabbit care. You can access them online.
Stay away from too many carrots. They have a high sugar content. Broccoli and cabbage are very *gassy* foods and should be fed in moderation.
For treats there are some excellent treats at Foster's and Smith. Try the Timothy Biscuits apple flavor, the Extreme Treats berry flavor, dehydrated apples, freeze dried banana, freeze dried strawberry. Also the Timothy cubes (found with the hay and pellets) are great for keeping those teeth worn down.