In organizing information for use, writing skills can be particularly helpful, especially in trying to summarize topics. Here are some resources I recently came across:
How To Make Notes and Write by Dan Allosso and S. F. Allosso – Learn to make effective notes on sources and your interpretations, then turn those into clear and compelling output. This link is to a website version of the book, an ePub version can also be downloaded.
The Documentation System from Divio – A theory of documentation composed of four types (tutorials, how-to guides, technical reference and explanation) with excellent explanation of the differences and examples on how to create these four types of documentation effectively.