Example Wishlist

I have been exploring Notch for a while now and I still have absolutely no idea how some of the features work and I could really use some examples:

How do the Raytracer Nodes work? I am specifically interested in Glass Shading.

How do the Shading nodes work?

Lumarca Geometry? Time Stretch? Unloaded effect?

I would love to know what these do so I can start exploring their possibilities.