There are multiple libraries at Purdue, but you can search for books in one central place: the Libraries' Catalog. This will tell you where books are located, and if they're available to check out.
If the Libraries don't own or provide online access to a book or article you want, log-in to InterLibrary Loan (ILL) to request the book from another library.
The call number describes the book, starting with the broad discipline and ending with the very specific topic and author, so books on similar topics/by the same author are shelved together.
Most books available online (for free) are older titles - published before 1923 and in public domain.
You could also use Google Books as a starting place, find a book you like, and then search in the Catalog to see if Purdue owns a copy.
1. At the Libraries search box, select Books & Media from the drop down.
2. Type in your search. You can search by keyword, title, or author.
3. The result list shows books and journals available both in-print and online.
4. Too many results? Not finding what you need? Refine your search with the options at the left.
5. Click on the title to see more.
6. The "Request Options" shows the location, availibility, and status of the book.
7. To find a library, search this campus map.