In virtually all circumstances where people are working together, they come to agreement in ways that short-change the interests of everyone involved. This landmark book shows practical ways to find out what other people want, and to devise better alternatives that create a "win" for everyone.
The authors do a great job of overcoming the preconception that many hold that working on problems means that you have to be unpleasant. The advice to be hard on the problems and easy on the people (building a relationship) is a key concept that everyone can use.
I have found this book to be one of the most helpful that I have every read, and I cite its lessons in my first book.
I had a chance to use these principles in a negotiating workshop with veteran negotiators, and I was struck by how few people apply the lessons of GETTING TO YES.
You will vastly improve your life if you read and practice the ideas in GETTING TO YES.
A helpful related book is GETTING PAST NO.