I've been hired by by them twice, in two separate cities.
First step was filling a very long online personality survey/questionnaire (which is supplied by a separate company called UNICRU), which is used to determine if you are a suitable applicant. This helps weed through the applicants on who is hireable. If you meet up to par and they're hiring, then begins the next phase of interviewing process. Sometimes they do an over the phone interview first, but most often you'll get a call for an interview in the with a manager or supervisor. They'll ask you about yourself, your interests, why you want to work at Best Buy, what department you'd be interested in working in, etc. but let me stress for you to be open, honest, and friendly (nobody wants to work with a secretive, angry liar). They're very good about telling liars or people just telling them what they'd think they'd want to hear. Remember the interviewer is a regular person too. After that interview, if you passed, you'll find out either on the spot or later to have an interview with the store's GM. At that point, it's almost guaranteed you've gotten the job. Just be open, honest, and friendly. If you pass the interview with the GM and s/he makes you an offer, you'll have to pass a drug test and a background check. If everything comes back good, they'll call you to get everything set up and schedule your orientation date. You might get the position you applied for, or the GM might ask you if you'd work in a different area depending on your knowledge or personality. I was offered both times if I wanted to be in sales, front lanes, or customer service.
To be honest before both my initial interviews, something had happened in my personal life that put me in a terrible mood. Typically I'm a very bubbly personality, but when I got to the interview, I was quietly stressed that I wasn't going to be hired because I couldn't be as perky as I normally am. During my interview I was friendly and honest, and I got to know my interviewers to an extent. Found common interests like music (One of my interviewers is a heavy metal fan along with a big gamer, as am I) or workplace initiatives (another interviewer and I shared a tendency for being very organized and a bit of neat freaks). If you know someone that works there who is a good friend or will vouch for you, go ahead and mention the connection. I had a few friends who had worked at one store in home theater and geek squad. Made making a connection easier. It's hard to set timelines for hiring because they change depending on the store and management. In one manager interview, he passed me on to GM's interview the same day. At the other store, the manager had to schedule me for the next week since the GM was out of town.