The following are some supplementary resources:

DICTIONARY
Merriam- Webster Online

GEOGRAPHY
www.geographic.org

ALMANACS
http://www.infoplease.com/
http://www.factmonster.com/

ART
Metropolitan Museum of Art
National Gallery of Art

INTERNET TOOLS
http://www.itools.com/lang/
http://www.itools.com

LIBRARY OF CONGRESS
http://www.loc.gov/families/

LITERATURE
Project Bartleby

MATH
Ask Dr. Math

NASA
NASA's Spacelink

NATIONAL SCIENCE FOUNDATION
http://www.nsf.gov

SMITHSONIAN INSTITUTION
http://www.si.edu/

WORLD HISTORY
http://www.bbc.co.uk/history/
http://www.historyworld.net/