http://www.aisc.org/
    American Institute of Steel Construction. Professional and content rich.

http://www.iit.edu/~hsbridge/database/search.cgi/:/public/index
    Construction and testing of model bridges.

http://abcdpittsburgh.org/
    Association for bridge construction and design. Link and Content rich.

http://www.faculty.fairfield.edu/jmac/rs/bridges.htm
    The geometry of bridge construction. Interesting but simple.

http://www.sfmuseum.org/assoc/bridge00.html
    Bridge photography of Golden Gate and San Francisco Bay Area.

http://eduscapes.com/42explore/bridge.htm
    Kids learning site regarding bridge education. Content rich.

http://www.historicbridgefoundation.com/ipages/links/links.html
    Historic Bridges and information. Link rich.

http://www.tfhrc.gov/pubrds/summer95/p95su23.htm
    Good article on safety and research.

http://www.howstuffworks.com/bridge.htm
    Good article on general bridge information.

http://www.goldengatebridge.org/
    All you would want to know about the Golden Gate Bridge.

INTERACTIVE SITES:

http://bridgecontest.usma.edu/download.htm
    Download this free software which has the tools to model, test, and optimize a steel highway bridge, based on realistic specifications, constraints, and performance criteria.

http://www.pbs.org/wgbh/nova/bridge/
    PBS sponsored site which tests your bridge knowledge.

http://www.jhu.edu/~virtlab/bridge/truss.htm
    Interactive truss building program… Build a bridge online!

http://www.pbs.org/wgbh/buildingbig/bridge/basics.html
    Bridge basics (grades 4-9).