http://www.travel.state.gov/passport/passport_1738.html is the primary passport start page for US citizens.
http://iafdb.travel.state.gov/ lists nearest locations to apply for a passport.
Light Fellows of all nationalities should ensure that their passports will remain valid for at least 6 months after their scheduled return dates. It is YOUR RESPONSIBILITY to make sure that your passport is valid and has the necessary number of available blank pages for your visa, if applicable.
Light Fellows may need a visa to enter the countries in which they will study abroad. The steps that you need to take will depend on your nationality and the country to which you are going. It is YOUR RESPONSIBILITY to make sure that you have the proper documentation. Your program's information materials should include information on obtaining a visa.
For information on entry requirements for a specific country, please go to the Entry/Exit Requirements section in the Country Specific Information for the country you are interested in at http://travel.state.gov/travel/cis_pa_tw/cis/cis_4965.html. You may also contact the U.S. embassy or consulate of that country for further information. International students should refer to their home country embassy Web sites.
Yale does have an account with CIBT to service the visa needs of the Yale community (http://www.yale.edu/travel/passport.htm#visa). Be sure to log in with the Yale account number to get the Yale discount.