Encyclopedias

Columbia Encyclopedia
www.bartelby.com
The Canadian Encyclopedia
http://www.thecanadianencyclopedia.com
Wikipedia
http://www.wikipedia.org/
Infoplease
http://www.infoplease.com/
Answers.com
http://www.answers.com/
Refdesk
http://www.refdesk.com/index.html
Credoreference
http://www.credoreference.com/home.do
Fact Monster – Online Almanac, Dictionary and Encyclopedia
http://www.factmonster.com/
Webopedia
http://www.webopedia.com/welcomead/
Nuttall Encyclopædia of General Knowledge
http://words.fromoldbooks.org/Wood-NuttallEncyclopaedia/