Applied for the job, got a call a few days later. This is considered the first interview and generally cover your availability as well as whether you still want the job, but most importantly to see if you sound confident. I scheduled an interview for the next day. Made sure to dress well, white button down shirt and khakis as well as dress shoes.
Showed up for the interview 15 minutes early as expected of any interview, and met with a supervisor. This was the second interview, and one of the important ones, as this will determine whether I'm worth getting to the final interview. I sat down with him, and we talked about availability and how I would fit in with them, as well as my experience and what my job duties were at my previous employment. That went on for a good 30 mins or so and after going to the back room for a few minutes, he came back out and scheduled the next interview two days later.
Showed up for the last interview dressed the same, and spoke with the general manager. This is where they decide if you get the job or not. Generally answered the same questions as before, and he asked about what I knew about the store as well as my hobbied. By the end he said that since I had sales experience, which is extremely important for Best Buy, as well as a good knowledge of computers (I told him I had a MacBook and an HP laptop, and I wanted to learn more about Linux as well.) He was going to hire me for Computers. After that the basic instruction sheet with next steps and how employment is contingent upon background check and drug test, and that I'd get the offer after that's done.
Just come off confident, and try to talk about what you like about electronics as well as what you're most knowledgeable in. I had originally applied for Multi-Channel Sales Associate but was then put in Computers based on my knowledge. Just because you may not be the right fit for one job doesn't mean they won't try to find a place for you, just be confident and dress well and show that you can learn fast and can sell.