The Power of a Positive No, written by William Ury, explores the art of saying no effectively while still maintaining positive relationships. The book offers a three-step process for delivering a positive no, which involves understanding your deeper yes, asserting your no, and finding a solution that meets both parties' needs. Ury emphasizes the importance of clarity, respect, and empathy in saying no. The Power of a Positive No provides practical techniques for handling difficult situations and turning conflicts into opportunities for collaboration and growth.