Yeah, this "Dummies" thread didn't work out that way. It turned out that even the experts didn't know how to use it right and this thread has flailed a lot sorting things out.

Indirect Light is Diffuse light that bounces off diffuse objects in a scene. In real life, it's how most light gets into corners and under tables and the like. It can add a lot of "realism", but can be slow to calculate.

On the Render Settings, you can activate it by checking the Indirect Light box. (A lot of the discussion here is about a different interface to the same thing. For starters, just try the Render Settings panel.) I still have some work to do to figure out what "good" settings are for the  controlson the Render Settings panel; start with the Quality low and ease it up. Also allow at least a few bounces.

Does that help?

Whichway