Dan John book

I highly recommend the newer book "Easy Strength", which is a collaboration between Dan and Pavel. While there is very little if anything "new" in the book (new stuff, at least of any lasting value, is extremely rare in the world of training), they do a very good job of laying out the principles and nuggets of wisdom from the true heavy hitters in the world of Strength & Conditioning theory and practice.  The concept of the Four Quadrants and what these imply for the nature of the training required for each level is very valuable and well done.  I would say the book is worthwhile whether or not you choose to implement the actual Easy Strength programs or totally believe in the specific philosophy involved.