I found a video series on YouTube by LWM. Learning synthesis with pure data, where he builds a typical synth in pure data and explains general points in DSP and synthesising sound. He's a bit like my old chemistry teacher, the intro has that 80s kinda new age tackiness and his videos aren't very short, yet I found them more resourceful than others to pure data.
I have send him a mail about the axoloti, he seemed excited, asked a lot of questions. That was a few months ago. I hope he's got one now and has joined the community already. I find he'd be awesome to do videos on how to patch synths using the axoloti, because he seems very knowledgeable, and that could help a few newbies.
We could collect a few links pointing towards learning resources and have them in a post in user guide, we could divide it into sections of specific topics. I don't know if anyone already has pointed out to make a wiki. It's probably a bit of work, I would mind helping with it tho.