The Basics of the Art of Lighting is a three part tutorial by Audri Phillips from Intel. Autodesk Maya is the tool used in this tutorial, but the concepts are universal and useful to learn in order to understand the light interactions that occur in the real world.
Ultimately, lighting is about controlling and shaping light and shadows, reflections, refractions, and even color-whether you do it on a computer or on a film set. This kind of control requires an understanding of how light works, the aesthetic art of lighting, and techniques for lighting. This knowledge helps you develop your eye so that you can look with understanding at your image, clearly see it, and know what needs to be done. By looking and learning as much as you can about color and lighting, you can decide which information to use to create your lighting design-be it naturalistic or stylized in a myriad of ways.