Getting to Yes: Negotiating Agreement without Giving In by Robert Fisher is a classic. It was first published in 1981 and reissued ten years later. Here is a PDF of the book for easy reading (and sharing!).
If you are about to ask for a raise, promotion, or buy a used car, this book is for you!
Getting to Yes offers a framework for “principled negotiation” for two or more parties to work together to best address their mutual interests with creative, objectively fair solutions.
In many ways, the method of “getting to yes” is similar to the practice of nonviolent communication. The goal is to remain neutral and objective while negotiating; Fisher uses the expression “separating the people from the problem” to describe it. Another element of the models encourages a focusing the negotiation on interests at hand. Unlike typical visions of hard-headed negotiations, this element encourages thoughtful questioning of the rationale behind positions instead of a quick response which may be presumptuous or charged.
The stand-out element, for me, in this model is the process by which the parties are encouraged to brainstorm possible options for mutual gain. The book offers suggestions for how to encourage looking a problems from varied perspectives and even suggesting outlandish options to encourage generation of more logical ones.
Fishers partner, William Ury, has a (well done) 30-video that covers the basics of the model. Check it out!