If you have never read this book: stop what you are doing, take the rest of the day off, read this, and prepare to have your mind blown. This is one of the most important books you will ever read in your life. I am not being hyperbolic. HTWFAIP (A horrible acronym) will help you understand how to communicate with people more effectively. Unless you are a hermit, you interact with people every day. This will make those interactions more productive.
Mind Blowing. This is crucial to you if you're a product manager, founder, or startup person. It gives you a simple way to understsand and communicate how your business will be effective with others. I can't recommend this book enough.
There is even a preview of this book here.
I have suggested many people read this book and continue to. It is one of the first books I read on marketing and after reading others, I still think it is the best. The book boils down the fundamental concepts of marketing into 3-5 pages. It is a good primer and from here you can go deep into each category.
Paradox of Choice explains when people are faced with too many choices, they feel overwhelmed and will typically not choose something because of it. If you are in sales, marketing, developer, or a designer this book can greatly help in understanding how to minimize everything you say and do. Too many choices are bad. A simple choice (A or B) is great!
Before you fund raise, this should be required reading. Venture Deals clearly outlines how to approach fund raising, and how venture capitalists think about investments. I am amazed at how many companies are going into financing without ever have read this. I also have a favorite quote in the book that I typically ask people, to see whether they have read it.