This is a difficult question. Taking care of peoples pets and homes is not as simple as it seems. There are forms and contracts you will need to design. You might need insurance or bonding just in case something happens when you are in the persons house.Yahoogroups has a pet sitting group.
http://groups.yahoo.com/group/AboutPetSitting/join I suggest you join it. Great people there who will help you. Also join your local rescue groups. You will make valuable contacts.Read everything you can on pets, care, training etc. You want to establish yourself as an expert on the subject.As for price, find out what others in your town are charging. Ask other pet sitters. I charge 2.5 times minimum wage for a sit. It's not enough, but I live in a depressed area and people won't pay more. Purrs,The Cat Lady