Like books in a public library, books in academic libraries are grouped by subject. The DDC - Dewey Decimal Classification (from OCLC) can help you identify call numbers for your subject. Then you can find where the call numbers are in the library.
Since books on your subject will likely be located together, you can also search the library catalog for a few relevant books and then browse the shelves around that book.
Enter keyword(s) that describes your topic.
Click on a relevant title, then look at the subject headings under Subjects
Write down the call number of relevant books and note its location. If the book you want is at a different campus library, click on the Request Copy link and have it sent to your campus library.