Start with a couple of quick searches of Summon (library catalog) and the subject-specialized database like Europa World Plus to get a feel for the type and quantity of sources available. Play around with the suggested search terms.
Background Information - Sometimes you need a definition or basic fact for your paper that you can't find in a scholarly article. Or perhaps you need a more basic understanding of your topic before diving deeper into scholarly research. This is where reference sources, such as encyclopedias, come in handy.