We might! You can find out by searching the library catalog. If the book you need is not strictly a "textbook" but is being used in a class as a text resource, then it's more likely we may have it.
Check our catalog for the title. Pay attention to the edition and publication date, since both are important with textbooks. If we have it, you can borrow it. Normally we would recommend interlibrary loan if we don't have it, but very popular (and expensive) textbooks are often difficult to find even at other libraries.
Here's another possible option: Your professor may have placed a copy of the textbook on reserve. Check under Course Reserves on the library's main page. If so, you and other students in your class may share the book, usually for 1 day to 1 week at a time.
And, of course, the Augsburg bookstore does stock textbooks. Renting them may be cheaper than buying them, and there may also be e-book options.