Reference works such as encyclopedias, research guides, and bibliographies are an excellent way to find background information and to get an overview of the current scholarship about a topic. 

Everyone is familiar with at least one reference work: Wikipedia. Wikipedia is an online, crowdsourced encyclopedia.

A bibliography is literally a list of books (and other works of scholarship), like the list of works cited at the end of your research paper. Published bibliographies are more extensive and comprehensive lists centered on sources about a particular subject, compiled and usually annotated by established scholars in the field. The right bibliography can help you quickly and easily find out about important scholarship on your topic.

Thematic collections of current scholarship, sometimes called "handbooks," can also be very helpful when you are familiarizing yourself with a topic.