This page from China has a (fairly complete) listing of embassies and consulates, mostly in the U.S. and Canada. Their home page is worth checking out, too, since it has information on immigration throughout the world.
This is the home page for the Department of State. It has links to, among other things, U.S. customs, immigration and naturalization, visa and passport information, travel health and security advisories, and internaltional parental child abduction.
This page has links to the Secretary of State, embassies and consulates, support for U.S. businesses abroad, international policy (both global and regional), travel, art in embassies, foreign service careers, and related foreign affairs sites. It also has a link to U.S. missions abroad that sponsor websites and links to international organizations such as the U.N., NATO, the World Bank, and the American Foreign Service Association.
EMBASSIES FOR COMMONLY-TAUGHT LANGUAGES
This list will provide a shortcut for accessing embassies of the the more commonly taught languages.
This site is a good place to start for information about France and the French language. However, many French students will already recognize the Alliance Française as an organization that has been very active in promoting the French language internationally.
This is the official site of the Spanish Embasy; however the Consejería de Educación has a more developed site in Los Angeles, CA, with many links to information about Spain and the Spanish language. This site has addresses and telephone numbers of Spanish consular offices in NY, Washington D.C., FL, LA, and Ottawa, Canada, as well as addresses and telephone numbers of the resource centers in CA, FL, IN, NM, and TX.