Had a phone interview before being called in for an in person interview. Phone interview was fairly simple, was about 15 minutes long. Be prepared to wait. Took a short computer assessment (do you do drugs, etc.), then waited for a guy to ask me about 3 or 4 questions. Waited a few minutes again until another guy asked me a few questions. One more time with the head of the actual Business Office with some more questions, after that he made the offer. The questions themselves were not especially hard, I thought I had prepared quite well but there were still a few I had trouble with. Definitely take a few days before the interview to remember some situations from your previous job and write them down so you can be reviewing them and have them fresh in your mind. Have questions to ask after (what is a typical day like, why is this position available, did someone quit, is there room for advancement, etc.).
Typical interview stuff, look them in the eyes, be confident, blah blah blah. Even the questions I had trouble with I tried to have a good, strong follow-up. It's an intimidating interview because you talk with so many people, but they were all nice and willing to talk back with you.