Always worth looking at that the US military do. (I say US because it seems that a hell of a lot of their instruction manuals are freely available. Shame I cant say that of the UK)
For me it was engineering. Years ago, I found some documents on metal work when I was learning to use lathes, milling machines, etc. Best resource available. It seemed old, but the information was invaluable. The thing that struck me was that, while it did do a quick over view of the basic methodologies and concepts, it very quickly focused on getting stuff done. It read like it was written for instant use. So, say you were a private stuck in the middle of no where, needed to make a part for, say, a gun and had a metal work workshop instantly available; this document would have said private making the part in something like an hour. Further, that part would work properly over a decent life span.
A basic rule of thumb for me is that what ever new thing I want to learn, I see if I can find a military instruction document on the subject.
How do you go about looking for such documents? Simple google "military instruction document"? Is there a term for those things? I know enough about the military that everything that can be put into an acronym is.
