I have just been told about the website 8bitworkshop.com! It's amazing!
I feel like writing a kernel for an Atari 2600 game is a lot easier than I originally thought.
Everything seems so cryptic when you first get into 2600 programming. As soon as you grasp that everything is about drawing the screen line by line, it becomes a little clearer.
Looking at other people's code is a must. I don't think I would have learned as much as I have without reading the code of past masters.