The Nine Planets
fast facts about the planets

Star Child: 
Divided into 2 levels great fast facts

Check you weight and age on any of the planets

Astro For Kids
Another easy to use, fact gathering site.

Arty the part-time Astronaut
Click on Adventure to learn about the planets. Activities - Time Machine gives your age on the planets or Gravitron to find your weight.

http://www.brainpop.com/science/space/solarsystem/index.weml?&tried_cookie=true
Great movies, limited number of viewing times.

http://www.fourmilab.ch/earthview/vplanet.html
You can view either a map of the Earth showing the day and night regions at this moment, or view the Earth from the Sun, the Moon, the night side of the Earth, above any location on the planet specified by latitude, longitude and altitude, from a satellite in Earth orbit, or above various cities around the globe.

http://kids.f9.net.uk/
Must have Flash, good for young students.

http://www.exploratorium.edu/ronh/solar_system/
Make a solar system to scale, this will calculate sizes for you.

Astronauts

http://collections.ic.gc.ca/science/english/bio/bondar.html
Roberta Bondar