FREE ONLINE ENCYCLOPEDIAS
http://www.bcps.org/offices/lis/Reference/encyclopedias.html

REFDESK.COM (Long list of encyclopedias)
http://www.refdesk.com/factency.html

THE INTERNET PUBLIC LIBRARY   (Search several encyclopedias at a time)
http://www.ipl.org/div/subject/browse/ref32.00.00/

REFERENCE DESK
http://mel.lib.mi.us/reference/REF-encyclopedias.html

YAHOO REFERENCE ENCYCLOPEDIAS
http://dir.yahoo.com/Reference/Encyclopedia/