The E-Myth Revisited is a classic (we would say THE classic) business book by Michael E Gerber. It is subtitled "Why most small businesses don't work and what to do about it". It was published in 1995, 15 years after The E-Myth was first published. And that was preceded by eight years of Michael's company E-Myth Worldwide. So this is no flash in the pan. Much experience and wisdom that led to this book - and it is still very relevant today. If there is one thing you can do to improve your business, read this book - and then implement its lessons. Reading the book will do nothing for you without implementation.
The first thing that should be obvious is the E does not have the meaning we would assume today. E stands for Entrepreneur. And the first thing he identifies (in the foreword) is that "people who are exceptionally good in business aren't so because of what they know but because of their insatiable need to know more". He also says in the same preface that the book is not about endings but beginnings in a never-ending game.
In the first chapter on the E myth, we meet Sarah - three years in business and the thing she loved (baking) she now hated. We follow Sarah as Michael helps her look at things afresh. Michael introduces the fact that a business needs three people to succeed: Entrepreneur, Manager and Technician. That alone is worth the cost of the book.
The technician is self-explanatory. Everybody has skills by which they earn their living. Most do it for remuneration, but some do it as a business. And that's where the other two come in. The entrepreneur is a big picture enthusiast - and generally is internally motivated. The manager is more detailed in their approach to life and business - and generally is externally motivated.
These two "people" are inherently opposites in almost everything they do - much as many married couples are opposites. The secret to true success is in combining their disparate skills. When they do this effectively, they can achieve far greater things than either could achieve on their own.
I could run through chapter by chapter - but Michael does it far better than I ever could. And there are other books and methodologies ready to part you with cash. But if you only buy one resource (and a paperback costs little) to learn the keys to making your business work for you, this is the one I recommend. But of course (and sorry for the repetition), the book will not change your business one iota. It is only as you absorb and implement the ideas you can expect to see change.