http://www.thomasregister.com
Thomas Register, a locator of companies, provides information on industrial products and services offered by U.S. companies

http://www.dnb.com
Extensive information and reports on companies and businesses

http://www.ansi.org
American National Standards Institute, info on U.S. Standards

http://www.uschamber.org
Federation of businesses, chambers of commerce, American chambers overseas, and trade and professional associations

http://www.bbb.org
Better Business Bureau, business guidance and dispute resolution