Astronomy for Kids, from Rochester New York, for Kids
http://www.frontiernet.net/~kidpower/astronomy.html

Fast basic facts.

Astronomy for Kids . . . and supervised adults
http://www.dustbunny.com/afk/

Astronomy - Astro for Kids, from Astronomy Magazine
http://www.astronomy.com/asy/default.aspx?c=a&id=1091

Astronomy Picture of the Day, from NASA
http://antwrp.gsfc.nasa.gov/apod/astropix.html

Astronomy Dictionary, from kidsastronomy.com
http://www.kidsastronomy.com/dictionary.htm

Astronomy Online
http://www.astronomyonline.org/

The Solar System -- Pictures of the Planets
http://www.the-solar-system.net

Online Explorations from Amazing Space, http://amazing-space.stsci.edu/resources/explorations/

"a fun, interactive way to explore galaxies, black holes, comets, and other fascinating objects."

NASA for Kids
http://www.nasa.gov/audience/forkids/home/index.html

Games, projects, and news.

The Space Place
http://spaceplace.nasa.gov/en/kids/

A variety of NASA sites w/ games, activities, projects, scientific information, and amazing facts.