The book, Sorbjan, Z (1996):Hands-on Meteorology, published by the American Meteorological Society, is an excellent source of ideas for teachers to use in the classroom. However, no book can be complete, so this web site...

This site, hosted by How Stuff Works.com, explains the science behind rainbows, including the bending and refraction of light. Using images and text, the site explains the process step by step, making it very accessible.