Visitors to StenniSphere, the visitor center at NASA Stennis Space Center, 'test' a space shuttle main engine in the Test Control Center exhibit. Credit: Stennis Space Center

• NASA's dedicated page for Informal Educational Resources: http://www.nasa.gov/audience/foreducators/informal/index.html
• NASA Jet Propulsion Laboratories Page for Informal Education: http://www.jpl.nasa.gov/education/informal/
• Additional NASA Resources for Informal Education: http://education.ssc.nasa.gov/informal.asp

NASA Visitor Centers:

• NASA Headquarters
  300 E St. SW, Washington, D.C.
  The NASA Headquarters Information Center offers some information brochures, mission decals and posters for free and sells various NASA publications and directories by phone or mail.
• Ames Research Center
  Moffett Field, Calif. 94035-1000 (South San Francisco Bay Area). Phone: (650) 604-6274
  http://www.nasa.gov/centers/ames/home/exploration.html
• Dryden Flight Research Center
  On Edwards Air Force Base (approximately 2 hours north of Los Angeles, California.) Bldg 4839, 4800 Lilly Drive, Edwards, Calif. 93523-0273, Phone: (661) 276-3449
  http://www.nasa.gov/centers/dryden/about/Dryden/tour.html
• Glenn Research Center
  at Lewis Field, 21000 Brookpark Road, Cleveland, Ohio 44135-3191, Phone: (216) 433-2001
  http://www.nasa.gov/centers/glenn/events/index.html
• Goddard Space Flight Center
  Greenbelt, Md. (15 miles east of Washington, D.C.) Greenbelt Road, Greenbelt, Md. 20771-0001, Phone: (301) 286-8981
  http://www.nasa.gov/centers/goddard/visitor/home/index.html
• Jet Propulsion Laboratory
  Pasadena, Calif. (near Los Angeles). 4800 Oak Grove Drive, Pasadena, CA 91109-8099, Phone: (818) 354-9314
  http://www.jpl.nasa.gov/events/tours/views/index.cfm
• Johnson Space Center
  Houston. The privately operated Space Center Houston. Admission fee. Space Center Houston, Johnson Space Center, Houston, TX 77058, Phone: (281) 244-2105
  http://www.spacecenter.org/
• Kennedy Space Center
  Cape Canaveral, Florida, east of Orlando. Spaceport U.S.A., Kennedy Space Center, Kennedy Space Center, FL 32899-0001, Phone: (321) 452-2121
  http://www.nasa.gov/centers/kennedy/about/visit/index.html
• Langley Research Center
  Hampton, Virginia. Visitors center located at the Virginia Air & Space Center in downtown Hampton.
  http://www.vasc.org/
• Marshall Space Flight Center
  Huntsville, Alabama. The privately operated U.S. Space & Rocket Center. Admission fee. One Tranquility Base, Huntsville, AL 35805, Phone: (256) 837-3400
  http://www.ussrc.com/
• Stennis Space Center
  Bay St. Louis, Mississippi. Free admission. Visitors Center, Stennis Space Center, MS 39529-6000, Phone: (228) 688-2370
  http://www1.ssc.nasa.gov/public/visitors/
• Wallops Flight Facility
  Wallops Island, Virginia (on Virginia's Eastern Shore). Free admission. Bldg. J-17, Wallops Island, VA 23337, Phone: (757) 824-2298
  http://sites.wff.nasa.gov/vc/