I think the only way we are going to grow our developer base fast enough might be train existing users to be developers. While there have been threads on learning paths for C and python, understanding the fundamentals for rendering, rasterizing, simulation, etc. are all probably desirable.
So I’d like to collect learning resources that can take someone from just a basic C/python understanding and bring them to a level where they can make a useful contribution to various subsystems.
This is a great intoductory tutorial to raytracing.
Same tutorial in pdf format
The next step might be understanding and adding features to a slightly more robust ray tracer perhaps the NORI educational ray tracer
Next might be the PBRT ray tracer/book
Then finally cycles and opensl
For simulation this series on fluid simulation is excellent, and covers a great deal of knowledge relevant to other simulations
Here are integrators which are relevant to most simulation
If you have learned any of these topics and know of good knowledge sources, please do contribute suggestions.