Proof of Citizenship
All applicants must provide proof of citizenship. This includes a certified birth certificate, certifications of birth abroad, naturalization certificate, certificate of citizenship or an undamaged passport. Minors require parental consent, proof of relationship, government-issued ID for parents or legal guardians and a photocopy of each ID.
Passport Photos
Applicants must submit two passport photos. Passport issuers enforce the photo guidelines very strictly. Go to a professional photographer and make sure he is familiar with the guidelines on the U.S. Department of State website.
Passport Cards
Passport cards are cheaper than passport books. Use them for travel to Canada, Mexico, the Caribbean and Bermuda, but only for travel over land or sea--not international air travel. Passport cards require the same documentation as passport books.
Visas
Some countries, like New Zealand, do not require a special visa for tourist stays of three months or less. For others, like China, you must apply for a special visa in advance even for a short stay. Check with the U.S. Department of State website for a list of visa requirements. See the link in Resources.
Warnings
Consult the list of consulates on the U.S. Department of State website before you travel. Report lost or stolen passports to the local U.S. consulate as soon as possible to avoid interruption to your travel plans. See the link in Resources.