To find books written about a specific person, do a Subject search in OSCAR (the library's catalog) and type the person's name (last name first).
If you are looking for books about a topic (not a person), do an Advanced search in OSCAR. If the first terms you type do not give you the results you want, try typing in various ways of describing your topic. Then, once you find some books that look like what you want, click on the Subject links that appear in the full records for those books, and you will probably find even more books on the same topic. (For example, if you type "Greek chorus," you will find a few relevant books, but clicking on the Subject heading "Drama -- Chorus (Greek drama)" will reveal additional books to choose from.)