Many Tolkien books are in the PR6039.O32 range on B2.
To search for books in Boatwright, use the Library Catalog. Start with a keyword search or "all words." Since some of the most common words you might search for aren't actually in the subject headings -- use terms from the subject headings if have trouble locating books.
If you are looking for information on a person, you should first use that person's name in a keyword search. However, many books will have information on persons that is not evident from the information in the catalog. To find these books, you should scan the tables of contents and indexes of books in the appropriate call number area.
You can search by book Title, Author, All fields or Subject.