To find books written about a specific play, do a Subject search in OSCAR (the library's catalog) and type the name of the playwright (last name first). For example, to find books about the plays of Christopher Marlowe, type "Marlowe, Christopher."
There are so many books written about the works of Shakespeare that special subject headings exist for books that discuss productions of his plays. Do a Subject search and look at the results that come up under these headings:
Shakespeare, William, 1564-1616 -- Dramatic production
Shakespeare, William, 1564-1616 -- Film and video adaptations
Shakespeare, William, 1564-1616 -- Stage history.
If you are looking for books about a more general topic, 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.
Your results will probably include printed books that can be found in the library building, as well as electronic books that can be read online. You can tell which books are e-books because no physical location is indicated, and the words "(Electronic Resource)" usually appear immediately following the title of the book. Click on the title of the book to open its record in OSCAR; then click the link in the middle of the screen to read the book online.