Congressional Research Service. CRS works exclusively as a nonpartisan analytical, research, and reference arm for congress. The CRS mission is to support an informed national legislature. C-Span is a public service created by the American cable television industry. Excellent resource for information about the Washington, D.C. foreign embassy community.
Most embassies provide in depth data about their countries.
Foreign Affairs Online. An excellent, comprehensive, site with links to the categories of reference, U.S. government, Foreign States, International law and International Relations. Great American Web Site . Arranged by broad category, e.g. executive branch. This site offers links to official government information worldwide.