An encyclopedia is a type of reference book. These are great resources for gathering background information on your topic, as well as for:
Defining important vocabulary words related to your topic,
Finding a basic overview and main issues related to your topic, and
Finding references to additional resources.
Encyclopedia Search Tips
Since encyclopedia articles focus on basic, general information about a topic, what you type in the search box should also be general:
YES: "Music" and "high school"
NO: What impact does music study have on high school students' overall GPAs?
Background Information Databases
Below are a few good databases for finding background information such as reports on topics, definitions and encyclopedia articles. In addition, Opposing Viewpoints can connect you with relevant newspaper articles.
Credo Reference also includes a great Mindmap tool to help you brainstorm topic ideas.