I would get there at 8:45 and not earlier. Save yourself the idle chat. Go to the third floor of the Plummer building and grab your name tag.
Dr. Hayes will present the program and highlight some of the advantages of UM. Don't be fooled by the schedule on the packet. It says the interviews start at 9:00, but Dr. Hayes will start talking at nine. When I was there some young woman raised her hand and asked Dr. Hayes if she needed to go to her interview, because it was past 9:00. She looked stupid but I think it was a legitimate question. You'll interview either at 9:00, 10:30, or 11:30. Hopefully they'll interview you first, so you can enjoy the rest of the visit.
After your personal interview, you'll go back to the room and talk with current students. You'll take a tour of the campus (which is fantastic), then a tour of the third floor, which is very small. I think it's the smallest program I've seen. You'll have plenty of time to ask questions. The students there clearly love it and are great ambassadors for the school. I hope I, and you, get accepted. Have fun.
Kevin