The Red Book samples included a short demo on OpenGL materials. The demo is quite old but is still valuable when considering the Phong lighting equation. In the original C source file several materials are defined and the resulting app produces an image such as the icon of this post.
This post contains a WebGL demo where the different materials can be applied to a model.




is available at EdX, by Ravi Ramamoorthi, a Professor at UC Berkeley. By the end of the course students should understand the concepts of 3D graphics, and develop programs that create images of a 3D scene with lighting, using both real-time OpenGL and GLSL programming, as well as offline raytracing.