IU Libraries usually do not have textbooks, but you can search for the book title in the library catalog IUCAT. Often textbooks have more than one edition, so you may want to check the publication year of the book you need.
If IU Libraries do not have the book, you can request it through Interlibrary Loan. The Libraries, however, often are unable to borrow textbooks from other libraries.
If we do not have a copy of your textbook for checkout, and you cannot get it through Interlibrary Loan:
Search Class Reserves to see if your professor has put your textbook on reserve.