Are you trying to find information that the federal government gathers? Here is a tool to try: GAO/OSI-97-2 Investigators Guide to Sources of Information: Federal Agencies Cabinet-Level Departments and Associated Agencies, published by the General Accountability Office, a.k.a. GAO. Here I was able to find the federal agency that tracks accountants and attorneys-- The Securities & Exchange Commission. Looking for retail stores that accept food stamps? -- Department of Agriculture. Real Estate Appraisers? -- General Services Administration. U.S. Savings Bonds? -- Try the Bureau of Public Debt in the Department of the Treasury.
Bibliorati says - for federal information sources a useful toolbox item.