I sat on a nomination panel for the first time this year. As a KP alum, I was hoping to find some candidates eager to attend KP and go to sea. But, none listed KP as their 1st choice. The candidates that marked it down 2nd, 3rd, or even 4th will be getting a nomination. There is great variation in interest from district to district.
There is no set formula or questions list. Each panel member generates their own questions. Therefore, info from your congressional district is most relevant. Some questions are candidate specific, others are used across every candidate.
Most panels consist of a mix of alumni from the academies and professional staff of the MOC. Most MOCs don't attend the interviews. Panels can change year to year and there can be turnover in the staffer that runs the process. So, even info from last year from your district is not guaranteed to be dead on.
Be ready for the obvious questions:
-Why do you want to attend USMMA?
-What do you want to study?
-What career do you want to pursue when you graduate? (This doesn't mean you have to have your whole life planned out, but it should show you have given some thought to matching your goals to the academy you are applying for)
-Your application has a weakness in the area of (grades/ SAT scores/ athletics/ leadership). What are you doing to address it?
-The spots are limited. Why should we choose you?
Be ready with specific examples to answer behavior interview questions:
-Tell me about a time where you had to confront a moral challenge.
-Tell me about a leadership challenge.
-Where do you see yourself in 10 years?
I wholeheartedly agree with the other commenters advice on professionalism and practice. I also agree with knowing about the academy and the industry. Read GCaptain, follow Women Offshore, talk to the coach for your sport, talk to alumni in your area (most of us can't shut up about it), find a local Propeller Club and ask to volunteer.
Finally, don't let your parents hound the staffer running the process. Take charge yourself.