Congrats everyone on your interviews,
The interview day begins at 11:30, you will have lunch with faculty and then begin the long dreaded "small talk" session which lasts the rest of the day. For those who haven't heard before, yes, you are stuck in a room with your fellow interviewees and student interviewers and yes anything you say and do is fair game for the commitee. But it's really not as bad as you think, and the committe members are TOTALLY cool.
Anyway, you will be called out for 1 faculty interview and 1 student interview (the faculty is scheduled, you'll receive your time when you arrive, but the student interview is just whenever). The faculty interview can last anywhere from 20 minutes to over an hour if you really get in a conversation (though they're usually scheduled in 45 minute blocks). The student interview is quick (15 minutes usually) and also BLIND. Only the faculty member will know your app, though the student will look at it before they vote.
Staying in Reed Hall is probably your best best. It's convenient and easy and there are plenty of students around to help you out. You can sleep in, or go to class in the morning with some students, whatever you prefer.
BWI is the airport, there are several ways to get into town. A taxi is about $30 or so, or you can take the light rail. IF you take the light rail, make sure that it's light outside (wouldn't do that in the dark) and that you are not in a hurry as it can take FOREVER. Take it to Penn Station, then get off and go to your left as you come out of the station entrance. There you can pick up the shuttle to campus (at Penn Station and St. Paul) which runs every 30 minutes or so. Make sure you are on the St. Paul St. side and not on the Charles St. side. Get off at the 2nd stop, which will be Broadway and Monument. Reed hall is just down the street on your right. You're looking for a typical yellow school bus which has a big "Local" written on it's sign. If you look closer it says Homewood/JHMI shuttle.
Otherwise, enjoy your interview day! If you've gotten this far, you've obviously got a lot going for you. Interviews here tend to be totally chill, nobody is going to grill you or make you justify why you did things. Just be prepared to talk about yourself and why you want to come to Hopkins!
The interview day will last till around 5. You may get out earlier, but I would not leave too early, even if you get done.
Good luck everyone! PM me if you have specific questions.