1. The ONE Thing: The Surprisingly Simple Truth Behind Extraordinary Results - Garry Heller

If you only will read one book about productivity, this is the one.

This book (affiliate link) presents the natural conclusion on the 80/20 rule and the crucial importance of choosing the right task. In the real world, it is often one simple thing that will produce over half of the benefits.

According to Heller, you should find out the one thing all the time and focus 100% on it. Nothing else is more important than starting the first step. You find out the one thing with the following question:

What's the One Thing I can do / such that by doing it / everything else will be easier or unnecessary?

2. The Paradox of Choice: Why More is Less - Barry Schwartz

Corollary to the above book, Schwartz presents a counterpoint to the desire for more freedom and options. According to the book (affiliate link), more choices ultimately lead to a worse outcome, especially if you want the best possible one. By being a "satisficer" instead, you strive for good enough and can circumvent this paradox.

3. The Effective Executive: The Definitive Guide to Getting the Right Things Done - Peter Drucker

An old classic by the management guru Peter Drucker. Fortunately, this book (affiliate link) is not limited to executives only but to all people. By learning to observe where your time goes, focusing on the most important task, and making informed decisions, you will rise in effectiveness.

4. Tools of Titans: The Tactics, Routines, and Habits of Billionaires, Icons, and World-Class Performers - Tim Ferriss

This book (affiliate link) is a wide collection of all the wisdom from various people at the top. Based on the interviews on Tim Ferriss Show, here is a practical set of best practices that people actually use. You do not need to read it linearly, just visit the chapters and people that interest you.

Moreover, there is also great wisdom from Ferriss himself. From the slow-carb diet, and a real-world MBA to earning your freedom and preventing suicide.

5. The Psychology of Money: Timeless Lessons on Wealth, Greed, and Happiness - Morgan Housel

This book (affiliate link) brings numerous lessons and general principles on how to be reasonable (not necessarily rational) with money. Drawing from multiple success- and failure stories, Housel illustrate the need to be aware of your own psychology and thought process. You do not need to win every time, because when you finally do, it will be huge.