Typically, Best Buy has three stages for their interview process, screening over the phone, in-store supervisor or manager interview, and a final interview with the general manager of the store.
I would say that knowing how mobile phones tie into daily life will help you frame your mind for the interview. Also good to know the different ways phone plans work.
Easy questions like "what would you do if a coworker was stealing from the company?". Managers were very nice and easy to talk to. Overall good experience and simple for a college student to apply.