Obtain a passport for yourself and the minor. A valid passport is required for the entire length of travel. You may pick up applications at your local post office or obtain it electronically at the U.S. Department of State's Bureau of Consular Affairs website.
Complete and print out a Parental/Guardian Approval for Minor to Travel and Medical Authorization form.
Have the nontraveling spouse/guardian take his ID and the completed Parental/Guardian Approval for Minor to Travel and Medical Authorization form to have it notarized.
Make a copy of the minor's birth certificate.
Carry all travelers' passports, the Parental/Guardian Approval for Minor to Travel and Medical Authorization form, a copy of the minor's birth certificate and all health and medical insurance cards with you at time of travel.