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 1 week. I interviewed at Best Buy in Jun 2013
Interview
I applied online and within 3 days got a phone call from the hiring manager. I had a phone interview after which the hiring manager wanted me to come in for an interview with the store manager. I did so that day. I nailed the in store interview and landed the job. All I had to do was perform a drug test the following week and I could start.
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.