Business.gov – Official Government Guide to Federal Government Contracting has everything you need to know about selling your product or services to the U.S. Government:

The California Department of General Services has a website: Selling to the State, with information to help “you understand how your firm can become a potential supplier to the State of California and how the State buys products and services.”

To sell to a Sonoma County agency or department see the website maintained by the Sonoma County Purchasing Division.

There are more great websites on the SCL Biz Guide to Internet Resources.