Over time, certain practices became the way we usually do things. These texts are the result of our effort to document the best practices which have been proven to work. Please take into account that none of this is written in stone: not only do we constantly improve/tweak/adapt the way we do things, we might also be wrong here and there, or our approaches may not work for the given problem. Please do not hesitate to raise any questions you have about them via our global discussions mailinglist!
The list of all the learning materials can be found here.