This site from the On-Line Physics Lab provides a clear complet outline of the properties of
both waves and particles and explains the evidence from experiments that have demonstrated
light's tricky qualities.
This article from a book by Rouse Ball on the history of mathematics discusses Isaac Newton's model for describing refraction of light based on light's being a stream of particles.
This section from the larger Wikipedia article on Isaac Newton does a nice job of listing and describing Newton's many contributions ot the theory of light and color.
Here's a series of articles about the nature of light from the Nobel Institute in Sweden. It includes information about light's wave-particle duality as well as reports on Nobel prize-winning research about light and electromagnetic radiation.
From Prof. Phillip Grandinetti in the Ohio State chemistry department, this page features a nice summary and explanation of the properties of light that make us conclude light displays both behaviors.