As far as Povray is concerned, the Internet is not flooded with freely accessible scripts, script collections and learning aids. But if you look for it - what I do from time to time - a lot comes to light.
I have created two pages in the Povray section that deal only with these topics. Both are still very clear, but I will expand and maintain them in the future. As always, pertinent information is welcome.
For everything else see Tutorials - Small and big ones and Model- and Scriptcollections.
Greetings from Cologne
Martin