Negotiate Like The Hostages' Lives Depend On It
Truly excellent book I'm reading to enhance my skills as a mediator: "Never Split the Difference: Negotiating as if Your Life Depended on It," by former FBI hostage negotiator Chris Voss.

It's an easy, fun, engaging read that debunks some accepted thinking on how to negotiate and is just filled with valuable information -- on a level you don't see in many books.

By the way, it's useful for everyone, not just those who negotiate for a living -- it lays out techniques for getting people to connect with you and be more amenable to doing what you want them to do.