As soon as you bring your baby home, be sure to provide it with half a cup of my feed/your feed mixed half/half (1/4 cup of each), until the baggie of feed I gave you is gone. This should be, if you mix it properly, about a week with the half/half feed.
If you're going to feed a pet store rabbit food, I recommend Kaytee Forti-Diet Pro Health Food
They sell this at most Petcos, but not at the PetSmarts I've checked. There are two different kinds you can buy. The adult feed and the feed for babies. The only difference in the feeds I think is the amount of protein and vitamins. Babies need more protein then the adults, to support their rapid growth. Most feeds have enough protein to support all ages of rabbits. Those are always the best, but not everyone has the space to store 50lb bags or the bunnies to eat it all up before it goes bad!
It also comes with little red treats that I just picked out and put into a baggie and fed as rewards when my house rabbit did something good.
I used to feed this food when I had just one pet rabbit, before I switched over to Albers when I started my rabbitry.