Activity:

Name the different sources of light at a fair.

Explain how light sources emit different colors.

Name how the following are used, if at all. Draw a picture of each.

Plane mirrors

Parabolic mirrors

Lenses

Prisms

Sources for answers:

1. Optics for Kids explains properties of light in kid oriented ways . Refraction  Reflection Light and color
2. Refraction
3. Waves, Light and Sound (Multimedia Physics Studio The Multimedia Physics Studios consists of a collection of GIF animations and accompanying explanations of major physics concepts. 
4. Ray Optics Excellent site
5. Interactive Thin Lens Demonstration
6. Electromagnetic Spectrum : an explanation of light as part of the electromagnetic spectrum
7. Nasa's Observatorium - Radar Imaging, False Color, Satellite Orbits, Spatial Resolution, Digital Imaging, Multispectral Remote Sensing, Thermal Infrared, Landsat's Thematic Mapper Bands, Reflected Infrared Energy
8. Patterns in Nature : includes Light, Reflection, and Refraction , Lenses, Mirrors, and Prisms , Color and the Spectrum , Optics in Nature , Supplementary Modules . An OPTICS KIT can be purchased to accompany this site.
9. Optics from the Museum of Physics The site also includes heat, electromagnetism and more
10. Go to Discovery School Online Click on Search Here. Then type Spectrum (or another appropriate optics topic) in the search box and click on Submit.
11. Fermilab's Pages of Light
12. Sighting the First Sense
13. How Light Works
14. The Mathematics and Physics of Rainbows
15. Polarized Light in Nature and Technology
16. Experiments with Diffraction Gratings
17. Solar Spectrum: Fraunhofer Lines Also look at the sections on sun, stars etc.
18. Solar Spectrum: Goddard Space Center
19. Solar Spectrum from  Online Astronomy See movies at bottom of page
20. History of Optics

Other sites for exploration:

Optical Society of America: Lists different sites where you can go to find out about optics.

For younger children,  The Color of Snow

Old links: May not be currently working

Rays using Lenses and Mirrors : This site shows ray diagrams : drawings of the path light takes when it encounters a lens or mirror. (Good demonstration)

Circles of Light: The Mathematics of Rainbows

This is the Rainbow Lab, a geometry project based at the University of Minnesota where the objectives include studies of Fermat's Principle, experiments to determine the angle at which rainbows appear in the sky, and to seek to understand the geometric properties of rainbows as they pass through a raindrop. There are excellent charts and questions to go with the topics. Here are clear basics for students entering the field, and some thoughtful challenges for advanced inquiry.