The University Libraries webpage, http://www.usd.edu/library, gives you access to thousands of resources. Look for the grey bar:
Books & More
Also known as One Search, is a search tool that allows you to quickly search many of the library's resources at once. One Search is great for searching the library catalog, some database content, and digital collections. Use One Search as your starting point for your research, especially if you are unfamiliar on a topic or resource type (book, article, etc.). One Search is a great place to begin your research, but use other tools for more in depth searches (i.e., databases for articles or the library catalog for books and journals). For more information, visit the One Search libguide or contact your librarian.
University Libraries has 200+ databases. For help doing specialized searches in the databases, contact your librarian.
These guides are created by librarians to help users with research assistance, library resources, or library guidance for specific subjects and courses.
Request materials from other libraries if University Libraries doesn't own it. Use your USD username: firstname.lastname and the password you use to access your USD email to register for an account. Once registered you can request electronic articles, physical books, or other materials.