1911 edition of the Encyclopedia Britannica - The best encyclopedia ever written was published nearly 90 years ago! And now you can find right here on the web! ...is filled with historical information that is still relevant today.
CIA World Fact Book - Terrific reference
Encyclopedia Britannica - view the complete Encyclopedia Britannica on line
Encyclopedia Mythica - an encyclopedia of mythology, folklore, and legend, and it presents an extensive variety of cultures, from Aztec to Latvian. The information available to browse through includes "over 6000 definitions" of all manner of mythological things.
Monstropedia - the largest encyclopedia about monsters...the ultimate online encyclopedia of monsters in myth, magick and legend.

Google Encyclopedia...Everyone knows about Google´s search engine, but did you know about Google´s e-encyclopedia? It features great sites in science and technology, nature, space, history, arts and entertainment and more, with lots of great images you can use in your next project.