Question: Why is it so important to use a reference work? Why, for example, would a researcher bother to consult a scholarly encyclopedia?
Answer: Reference books help researchers contextualize their topics and in turn begin to ask the right questions. Reference books set the stage for more efficient database searching; researchers cannot elicit relevant search results if they don't know which keywords (or search terms) to use. Scholarly reference books also contain bibliographies that lead researchers to the most respected secondary and most useful primary sources on a topic. In short, reference books are a great way to begin your research.
Encyclopedias are an important first step to historical research. Use them to find an overview of the topic.