There is no interview process. As long as you pass a physical/mental/ drug exam, then you are good to go. You must also pass the ASVAB so don't blow it off in High School.
I applied through a recruiter. I interviewed at US Marine Corps (Hyattsville, MD) in Mar 2008
Interview
Hiring process begins in college and depends largely on whether or not the candidate wants to pursue a commission through NROTC or Officer Candidate School
Interview questions [1]
Question 1
Grade Point Average is a major discriminator as is an applicant's disciplinary record