First, they'll give you a call and ask you a few questions on the phone. Mainly stuff about you, who you are, what you like to do.
Then they'll call you in for a skills test where you basically go in, take a small quiz on the computer and listen to a few calls to decide if that's the type of job you're looking for.
Then they'll call you in for an interview in person. When you go, dress business casual, but be happy and don't be nervous. The people there to interview you are SUPER sweet, it's not a group interview, so it's you and the person interviewing you and they just ask you cliche interview questions like where you've worked in the past, what was one way you took a bad situation and made it good, etc. Be ready for those. They never caught me off guard with their questions.