This is not a conventional golf instruction guide. If you're looking for his titles on the mechanics of the golf swing, then the list is long.
Break 100 Now: From Hacker to Golfer in Just 90 Days
How to Break 90: An Easy Approach for Breaking Golf's Toughest Scoring Barrier
Total Golf
The LAWs of the Golf Swing: Body-Type Your Golf Swing and Master Your Game
This book sensibly outlines a method to play to your full potential. This is a true book covering the mental game through using your mind to prepare through evaluating yourself. So you can hit a straight 250 yard drive, but can you chip, putt or hit approach shots with equal accuracy?
There are several methods that the author improves your game through self assessment and self critique. Through a detailed analysis, you determine your strengths and weaknesses. Additionally, the author focuses upon positive thinking and target oriented play. What this book focuses upon are mental keys. A valuable section is what 'not' to do.
I admit the concept of reading golf strategy is quite dry. There are boxes that feature vignettes that tend to keep your attention.
Through my personal experience in playing and reading, I do what is outlined to a great degree to improve my game but this book really ties everything together that I learned along the way. It is more practical than Harvey Pennick's book, through more concrete plans, or even Raymond Floyd's, Master's Guide of Scoring.
The Elements of Scoring: A Master's Guide to the Art of Scoring Your Best When You're Not Playing Your Best
Harvey Penick: Little Red Book
A complementary subject to this book, written by a different author is another book that I recommend:
Golf: The Mental Game
I recommend this book to a beginner who has had some lessons and plays with some regularity. This is also good for a player in a plateau in their golf potential. Lastly, this is a good book for those people who have a natural talent/temperament for the game but want to make it to the next level.