I'm looking for online open-source / generously licensed textbooks, papers or tutorials.
Think of stuff like: http://neuralnetworksanddeeplearning.com/
Why? I'm currently running https://chimu.sh --a collaborative learning platform. Quick explanation: Chimu combines an e-reader with a Stack Overflow-like Q&A forum. As people read, they can view others' questions and ask their own. Demo here (desktop works best).
I need to seed the site with initial content, and I figured LW would be a great place to ask.
With this in mind, what are good online tutorials / textbooks that people here have learned from? Is there any book or paper that you wish that you could discuss with your friends?
Fyi, the link to your site is broken for those viewing on greaterwrong.com; it's interpreting "--a" as part of the link.