You need to contact the department in question, and they will be able to direct you to the person (likely a secretary or administrator) who is in charge of your rotation. It's very school dependent how much info they will give you. I've seen both ends of the spectrum.
One school gave me a detailed schedule of who I'd be working with each day, a reading list, and a bunch of info about the rotation. They even had scrubs in my size waiting for me in the department office. They helped me to get my badge and computer logins on the first day.
The other school sent me a 2 line email listing the hospitals I'd be at each week by initials only. I actually had to do research to figure out what the initials meant. Even with multiple phone calls and emails, no additional information was forthcoming.
With aways you really just have to stay laid back and go with the flow. You are out of your element. You will have a bunch of situations where you don't know what to do, and you just need to do your best, and ask a resident before doing something stupid.