Reference book are great resources for getting a basic overview of a topic with which you are unfamilar. They also often contain IMAGES, VIDEOS and MAPS.
An excellent free resource for getting topical overviews of subjects related to the greater Philadelphia area. Also a source for IMAGES and maps
CQ Researcher provides reports written by journalists, footnoted and fact-checked. Full-length articles include an overview, historical background, chronology, pro/con feature, plus resources for additional research. Graphics, photos and short "sidebar" features round out the reports.
Credo Reference provides access to a large number of encyclopedias, dictionaries, thesauri and other reference books. Subjects covered include art, biography, history, literature, music, religion, and science and technology
Encyclopaedia Britannica provides information and instructional products used in schools, universities, homes, libraries, and workplaces throughout the world. Britannica is online, in e-books, and on mobile devices.
Encyclopedia of American Studies provides information on history and cultures of the United States, from pre-colonial days to the present. Great source for IMAGES
Funk & Wagnalls New World Encyclopedia provides encyclopedic entries covering a variety of subject areas. The database contains IMAGES, biographies as well as information on research needs of middle and high schools students.
Gale Virtual Reference Library is a database of encyclopedias and reference sources for multidisciplinary research.
Sage Knowledge provides full-text of major reference works published by Sage Publications
The list above is a recommended list of databases. If you were unable to find what you are looking for, take a look at the entire list of reference databases and select your own : Complete Reference Database List