Librarians often turn to databases like Credo Reference and Gale Virtual Reference Library when helping students conduct background research. If you're looking for a resource that goes a step beyond that, take a look at Very Short Introductions.
Very Short Introductions began as a print series in 1995, offering brief informative introductions to a diverse range of subject areas in Arts and Humanities, Law, Medicine and Health, Science and Mathematics, and Social Sciences. Titles include The Renaissance, Science Fiction, World Music, Game Theory, and more. Many of these titles are also available in print in the COD Library.