A home based business wouldn't be a bad thought. If I were to do something like you, I'd probably convert my garage into a store front of sorts, and keep a select amount of animals. Very few. The shops I frequent have signs posted about "We don't make our money on turning over live animals, we make it in food! Remember us when you need to feed your pet!". So, in all honesty, most places sell food. Dog food, cat food, bird feed, crickets, roaches, mice, and rats. Thats where the money is. And thats what will bring the customers. If you can beat petco, petsmart, or your next door neighbor on price and availability of food, then you'll get customers.

Online is a MUST these days, and ignoring or neglecting it will hit you in the pocketbook before the mouth.