Obtaining a U.S. Passport is very time consuming but well worth your time. There is a rumor going around that in the next year or two, you will be required to have a passport to even travel by air, domestically.
You can obtain more information by clicking on this link, which will further assist you.
http://travel.state.gov/content/passports/en/passports/first-time.html
and also
http://www.state.gov/documents/organization/212239.pdf (Download PDF)