I have used mindmapping a lot lately. I usually create one overview mindmap for the overall structure of more complicated topics and submindmaps for interesting subbranches.

I'm still looking for the ideal process of capturing what I know about a certain topic. Programming is very different from other topics from my experience because you usually want to include syntax or some short examples and so forth.

I think it may be better to use a wiki or something for programming but would love to hear how other people structure their stuff.

Mindmaps works really well for non-fiction books and lectures. I use them as review and overview tools and love it.

FWIW, I prefer doing it on paper because I feel like I'm a ton less creative when using computer tools.

Oh and if someone knows of any online courses a la "learn to draw icons for mindmaps" I'd love to hear about it. My drawing skills are mediocre to say the least and it's something I'd love to work on.