One way to determine what textbooks are needed for your class is to review the syllabus for the class. Course syllabi are generally available at least a week or two before the class begins. Your instructor may have posted the syllabus on a Blackboard course page. See the link to Blackboard below.
If you're an on campus student, use the link below to access the CMU Bookstore website. You can then search for textbooks by course.
Global Campus students can purchase textbooks through MBS Direct at the link provided below. You can also search for your course at the MBS website to see a listing of required textbooks, then order if you wish.