Find a broad background source. This will help you:

• Refine and narrow your topic
• Discover background information
• Identify keywords that will help you search for other resources

Reference works are full of overview articles and are perfect starting points for your research. Not only do you get authoritative content, you also get a recommended reading list which will lead you to other high-quality content. 

Use this search box to find background information by entering a basic keyword, the Boolean search command "AND,"  then the word "reference" or "encyclopedia."

For example,  Type 2 Diabetes AND reference, or  Alzheimer's AND encyclopedia

An introduction to using Wikipedia for Academic Research.

Wikipedia should only be used as a preliminary step to better background resources but it can be very useful for locating keywords or key phases, notable researchers or authorities on your topic, and reliable, high-quality resources.