The full title is: "Modern Fly-Casting Methods: Decades of Fly-Casting Wisdom from America's Fly Casting Coach" by Lefty Kreh
One of the interesting things about this book is that Mr Kreh completely dismisses the old fashioned method of using a clock face to learn to fly cast. Start with the rod and 9 o'clock bring it back to 1 o'clock and back forward to 9 o'clock. I remember learning to cast using this method. I also remember getting frustrated and giving up on it and going back to my spinning rod.
At some point I decided I was going to learn to fly cast no matter what and muscled my way through to be a reasonable caster. Reading this book brought a smile to my face and vindicated my frustration learning to cast using the clock face method.
Mr Kreh literally begs people to learn to cast properly. He has personally seen too many people who are horrible casters because they were taught using the old fashioned clock face method. He also has heard too many stories from guides whose clients will spend a small fortune on equipment and a trip to some far off location and the clients don't catch anything because they can't cast. Along with learning to cast, he urges people to practice casting. They will catch more fish. (But we already know that.
The book then goes on to describe Mr Kreh's modern method of fly casting. He describes a reasonable set of 5 keys that a caster can use to visualize and create a good cast. I won't go into this too deeply because it is basic single handed overhead casting technique.
As someone who is learning to Spey cast reading the second half of the book was extremely frustrating. In the second half of the book he describes the roll cast and change of direction casts. A fisherman would be far better off learning a basic switch cast and single Spey cast than trying to master these modified overhead casts. During his description of how to make a long roll cast I thought Mr Kreh might accidently describe a switch cast but alas no. He has the whole line crash down behind you and then rip the whole thing off the water during the forward cast.
I can reluctantly recommend "Modern Fly Casting Methods" if you want a basic introduction to overhead casting with a single handed rod, but skip the second half of the book and learn some basic Spey casts instead.