You may be in a class where the professor has placed books, videos, etc. on reserve in the library with limited circulation. Course reserves are located behind the circulation desk. You may tell a staff member at the circulation desk the name of your professor and/or class, and they will help you check out an item from reserves. Reserve items must remain in the library, and are generally due back in two or four hours, depending on the class.
You can also see what's on reserve for your class by looking in our library catalog, and clicking on the course reserves link. From there you can select your professor's name, or what course you're in.