Reference books are useful for getting an overview of a topic, finding references to other sources on the topic, and for finding background information, on say, and author and her work. Here are just a few examples of reference works that might be helpful for some of the topics you might explore for your "Angels Report" assignment.
In brief, our library catalog is the search engine that will tell you what books we have and where they are shelved. You can search by "all fields" (that is, the information in the catalog, not all of the contents of the book) or by author, title, or subject. Because catalogers describe the subject of books as a whole - rather than going into detail about everything the book contains - your searches will work best if you keep your search terms quite general.
Once you have a list of results, look for the call number - a letter and number combination that indicates where the book is shelved. Some books are shelved on the upper level and the rest are on the main floor. (There's more information available on how call numbers work. They take a little getting used to.)
Once you've located a book that looks interesting, browse the shelves around it. The Library of Congress classification system used in this library puts books on the same subject together; because you can look directly at the books while choosing, browsing is an effective way to discover useful sources.