The requirements vary from state to state. But in general the type of permit you need depends on the types of products, and how you sell them. The best place for you to start is to head to your county health department and get a packet that should include applications and the requirements.Another avenue, is your states Department of Agriculture if you are wholesaling. In the state of Washington, it's called a food processors permit.
Above all else, ask questions of which ever agency is appropriate for your business.
Good luck to you as you embark on this project.