Why hello!
As I'm in the process of researching how to make my own TTRPG, I guess it's a good idea to document cool things I found to help out with the process!
So here's a non-exhaustive list that I found helpful to ramp up my knowledge of TTRPGs, and make worldbuilding and GMing better!
The Lazy DM:
https://slyflourish.com/lazydm/
This distills the Dungeons and Dragons Dungeon Master's Guide into simple advice instead of a full textbook.
Game Master Advice for Neurodivergent GMs:
https://www.youtube.com/watch?v=Oyh_ALgjyCo
Starting Dungeons and Dragons for cheap:
https://www.youtube.com/watch?v=tm_mIKnOOVU
A framework for worldbuilding:
https://www.youtube.com/watch?v=GJMaOLlU9gI
Land of Eem quickstart guide:
https://landofeem.com/quick-start-guide/