This is the booklet on flexibility I always wanted to read but could never find, so I wrote it myself.
It's an excellent companion to "The Booklet of Bodyweight Power" for people interested in real "all around fitness".
This booklet is not about wedging yourself into funny positions and just sitting. There are no "stretches" in this booklet. It's about enhancing flexibility by developing strength at further ranges of motion. Real flexibility is moving flexibility! Not only being able to go there but be able to apply force and control while you are there--being able to do something more than wiggle into a funny position and grit your teeth.
Martial artists, particularly grapplers will find much of interest in this booklet. However anyone interested in flexibility that they can use, will find just as much. Most writing on strength focuses on applying force and moving from standing, lying or at least comfortable and set up postions. This booklet focuses on applying strength and moving from wherever you are, by choice or necessity. I guarantee there are things in here you have never seen or tried. Just like its companion book on bodyweight exercise, this one isn't full of abstract theory, big pictures, pleasant graphic design elements or anything that isn't about getting down to the real work.