Reference sources (such as encyclopedias, handbooks, atlases) are excellent tools, especially when you are beginning a research project. They give broad overviews, orienting you to the larger context in which your topic occurs. They can provide definitions and give you ideas for search words. They might also clue you in to the major thinkers in your area. Sometimes they provide resources for further reading, giving you an instant source list.
Books are shelved in general subject categories using the Library of Congress classification system. You may want to supplement your use of the catalog with browsing shelf areas for your topic.
For instance, you'll find many works by and about Jane Austen in the PR4036-PR4037 areas in within the 19th Century English Literature section (although Jane Austen resources can also be found in other sections).