When applying for a US passport, you must show up in person at a passport acceptance facility (unless you are simply renewing a visa that is undamaged). There, you will need to fill out application forms, which you can also get online. If you prepare these documents in advance, it will greatly speed up your appointment and passport application. All of these forms can be downloaded from http://www.travel.state.gov/.

Which Form Do I Need?

The basic passport application form is the DS-11 form. This is for first-time applicants, or those renewing a passport that has been lost. In addition, you must use this form if you were under 16 when you applied for a passport but now are over 16. This form must be submitted in person, but it makes things easier if you have it prepared in advance.

If you are renewing your passport, you need to fill out a DS-82. This form can be mailed in, with your original expired (but undamaged) passport attached. Simply include payment, and your new passport will be sent to you. There is no need to go in person if you are renewing a passport.

If you lose your passport, you must fill out a DS-64 as soon as possible. This is so the State Department can invalidate the passport so that it can not be abused if found or stolen. Once this is taken care of, you also need to go in person and apply as if you are getting a new passport (with a DS-11).