If you're a guy, definitely go suit and tie. Girls, dress formal and appropriate, you know the drill. For the tour, the girls were offered the chance to change into more comfortable clothing. At no point did we have to carry items around so don't worry too much about bags.
The day started the night before. Those who get invited to interview also get invited to stay with a student host the night before. It's a great way to see where students live and get a head start on asking questions about being a med student and Mount Sinai. At 8:30 everyone meets in the school, not far from the dorms if you stayed with a student. There were 12 students for my interview day, almost all of us were engineering majors. There was breakfast and the deans of the programs gave a short overview. Everyone is given a folder with information and a personalized schedule with who you are interviewing with and when. Current med students are invited to eat breakfast with you so you have more opportunities to hear their experiences. Both interviews are about thirty minutes one on one. They are with MDs, deans, or PhDs at the school. Then there are two students who act as your tour guides. They lead you to lunch in the student lounge and then around the various buildings. That pretty much concludes the day!