Georgia State University
Georgia State University: Hyper Physics: Scattering Concepts
A collection of several pages explaining the principles which underlie Rayleigh scattering of light.
Synopsys
Synopsys: A Gentle Intro to Optical Design: Why Is the Sky Blue?
Discusses Rayleigh scattering in plain language and attributes the blueness of the skies to this phenomenon. Discussion of scattering is just one topic of many on this lengthy page of optical topics.