Just got this through email. Hope it helps.
"We ask that you bring to the interview your logbooks and licenses for us to review, two forms of identification (one of which should be a picture ID), and a photograph you can leave with us."
"Please arrange to bring with you to interview one of the following documents:
- A valid, unexpired Passport
- An original birth certificate with raised seal
- An original U.S. naturalization certificate with raised seal, form 550 or form N-570
- An original certification of birth abroad
- An original certificate of US citizenship, form N-560 or form N561"