Like the E-myth revisited from Michael Gerber this book is a must read for anyone running their own business. The big advantage of this book over the E-myth revisited is that it is more concise.
This books takes the best bits from the E-myth revisited and condenses them into an easy to read, thought provoking way of looking at a business. In essence, most people in small business spend all their time doing the work, rather than building systems that allow other people to do the work for them. As a result they struggle to achieve the success and happiness that they desire.
If you want a quick introduction to the methodology that is the E-myth then this is a great start. It will start you thinking about working on your business rather than in it.