The Office of Student Life posts used textbooks for sale by students.
Sometimes an instructor will put a book on course reserve in the library, so that they can share a copy of the textbook with students in their class. The instructor determines the loan period. Oftentimes textbooks are Library Use Only, so you can use the book in the Library or photocopy pages from it, using your Student ID.
If your instructor does NOT have a book on reserve, you can ask them if they can get an extra copy to put on reserve in the Library.
The following websites sell/rent textbooks. This list is not comprehensive, but rather suggestions to get you started if you are having problems locating your textbook. These are independent sites and are not affiliated with MATC.