The last resource for today is as unconventional as it is helpful. At least if the MOS 6502 is still your object of desire, and instead of Commodore you rather feel an attraction towards Apple devices.

And if you can do without HTML and CSS, and if a simple filesystem structure paired with a webserver is enough for you, you might find enough reading material for the upcoming summer with the following:

Programming 6502 Assembly is only one of ... many resources on the server of asimov.net. We have counted a total of 38792(!) individual files. 😵

Besides a lot of documentation there are applications, emulators, tools, games, magazines, hardware, source code, you name it. Everything that typically accumulates in 20 years of collecting.

What can be found in the archive, is not yet in the public domain. But we assume that the operators have completely cleared the copyright.