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 applied online. The process took 3 weeks. I interviewed at Best Buy in Jul 2011
Interview
First there was a phone interview asking previous experiences questions, after that they decided to bring me in for my first interview. The first interview was a packet of questions about previous experience answers what I could bring to the company. Then there was a second interview and my job offer at the end.
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.
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.