For background information, you may want to use a Reference source, such as an encyclopedia. The 2 tabs connected to this page each list suggestions for such materials. The first page suggests several options for BU databases and lists a selection of examples from each.
The second page offers some suggestions from the BU Library print collection.
If you want to look for both print and online resources (including encyclopedia, dictionaries, and other materials) on your own, you might to start with the BU Library Catalogue or one of our other databases.