This is one of my favorite leadership books. Not because it's written by a Navy SEAL or ex-Admiral, but because it's simple.
The premise is this: The good Admiral lays out a mantra from the SEAL team and a quote applicable to the subject. He then converts the mantra to a common leadership position. For example, 'Death Before Dishonor' at face value might not be the right answer when facing, say, an argumentative employee. However, after the lessons are explained in 10ish small pages or less, you are left with the root of the lesson: 'Be a person of integrity.' Which in the aforementioned case is much more helpful. If you are a person of integrity and are loyal to both your commander and the men under you, you will find guidance to gain success.
This book is a great way to help you sort through leadership problems in the heat of the moment. It's significantly less of a read compared to, say, 'Once an Eagle' or 'About Face,' both of which are excellent books, by the way. They do require some real thought on how to make the successes found in the characters of these books apply to the current situation you may find yourself in.
The beauty of this book is its simplicity and generality. The lessons work. Of course, what needs to be said is my strong opinion that you can never make a real leader by exclusively reading or studying. It takes time gaining experience and facing real challenges, whatever they may be. What this book is, is if you find yourself in any leadership position and need some guidance - this is your book. Pop it open in the mornings or when you're in the middle of a big leadership problem. With some thought, your answer is there.