What about the idea of having a Calibre Wiki?
Wiki's (curated knowledge repositories), are "organic" in the sense that they can grow as structure demands, they have hyperlinking capabilities built in and they would allow "levels of nesting" so that topics can move from General Overviews to General Capabilities, to General task, to more specific tasks, to recipes.
Forums are terrible places to record knowledge, because there is no index and topics quickly become very large, and begin to split into different subject areas.
Wikis also allow people with the time to help. They encourage participation and aren't mired by release approval processes.
Here is an example of the main wiki for the Python Programming language (the language Calibre is written in) which can give a feel of how a Calibre Wiki could be structured. (think conceptual, not specifics)
http://wiki.python.org/moin/