Reference works provide overviews of topics, ideas for search terms, and sometimes provide citations or recommendations for future reading. They are essential resources for when you are starting your research, as they will provide the broader context of your topic. They are also useful to consult midway through your research (or even toward the end), as reading a broad treatement of your topic can help you identify any gaps you may have in your research.
Reference books are located on the Beck Hall side of the library's main floor. While they cannot be checked out, you can scan pages using the library scanners.