Reference sources are a good place to find background information on your topic. You will probably not end up citing these resources in your final project, but they are useful for figuring out how experts are speaking about your topic, and orienting yourself within the history of a topic. Many reference entries also have reading lists that can help to lead you to additional resources on your topic.
"Reference sources are authoritative works that help you locate information about people, facts, and ideas. These sources can help you find the date of an important event, major achievements of an individual or organization, or a definition of a term or concept. These books are often used to find specific facts, rather than written to be read cover-to-cover..."
Source: Research Like a Librarian
The Bothell Campus Library has reference materials online and in print. Most of our newer reference sources are online. Older print reference sources can be found in the third-floor stacks related to their subject matter, and most of these reference works can be checked out.