Ben Benavides, retired US Army master trainer, is as good as it gets in Army OSINT, but not widely enough known. He should be in charge of creating the Army OSINT Handbook and training program, AFTER we put CIA in its place and establish that overt HUMINT is OSINT and cannot be constrained by those who refused to be serious about overt human sources (CIA also forbids its own Open Source Center from talking to overt Subject Matter Experts (SME). Really. We do not make this stuff up.
Also by Ben Benavides:
2016 Ben Benavides OSINT 2ool Kit On The Go Bag (Bag O’Tradecraft)
Ben Benavides: Exploring Social Media Web Sites: A Guide for the Open Source Analyst