Don't wait for the forms, start scheduling now. I didn't get the forms through snail-mail until I came back from the interview (they were so disorganized that they actually had to email them to the interviewers a few days before the interview). You need to call in at least a week or two in advance to stay with a student, so if you want to do that you should call asap to schedule it. If you need to book a hotel, just visit their admissions website (they have phone numbers listed of hotels that offer discounted rates).
They also sent a form that asked if it was okay to be interviewed by a student. I never submit that form and I had no problems, so don't stress about that.