US Passport Agencies 
List of all US passport agencies and the process of obtaining passport. Site also provides information passport offices, passport services, lost passport and second passport. - More details
http://www.passportvisa.org/Passport/Us-Passport-Agency/Us-Passport-Agencies.html

US Passport 
Detailed information on US passport and other details regarding obtaining US passport - More details
http://www.passportvisa.org/Passport/US-Passport/US-Passport.html