Visit the U.S. Department of State website to get the proper form. You must fill out form DS-11: Application for a U.S. Passport. You can download the form at the State Department website.
Have two photographs taken to submit with the application for a passport. The photos must be 2 inches by 2 inches, be in color and be printed on photo quality paper. The State Department offers a tool to help you size and crop a photo on your own computer.
Present proof of citizenship with your application. While other forms of proof are usually acceptable, In the case of a naturalized citizen, your Naturalization Certificate is required.
Submit Form DS-11, the photos, the proof of citizenship and a copy of the proof for the State Department to keep on file along with the applicable fees.