One option is to dive in with Peter Shirley's ray tracing intros linked at the top of http://www.realtimerendering.com/raytracing.html http://www.realtimerender

One option is to dive in with Peter Shirley's ray tracing intros linked at the top of http://www.realtimerendering.com/raytracing.html http://www.realtimerendering.com/raytracing.html These will get you a quick overview and get something rendering. PBRT is a great follow up to really understand the physical underpinnings and get more into the theory of how to do things correctly and efficiently.