I am a bit lost trying to understand different kinds of lights. I want to know if there's any tutorial about lights and which test are the best to learn about lights.
The lights in jME are the standard ones of OpenGL… Ambient, Directional, Point and Spot. Pretty much any tutorial is good for understanding this:
Also check the TestLightState in the jmetest examples.
Actualy the jME User's Guide contains a rather large section on lights:
Yesterday I read the JME user guide and It was very useful to undertand the general idea. Now, I'm going to study the OpenGL tutorial.