Use encyclopedias and dictionaries to find background information before you begin your research in earnest. Not only will a reference article bring you up-to-speed on an unfamiliar topic, but many include bibliographies as well, which can give you a great place to start locating sources.
The library's reference collection is on the 2nd (main) floor. Use the blue Library of Congress handout (copies are available near the research help desk) to identify which section might be relevant to your particular topic.
Here are three examples of encyclopedias you may find useful. We have much more than just this, though, so remember to browse!