The Situational Leader
Terrific early work by Hersey (without the collaboration of Blanchard) in which he clearly sets out the case for adapting one's leadership style to suit the context. You don't hit a nail with a saw he says so why have a one-style-fits-all when it comes to leadership? He uses visual tools to dissect the different leadership styles ranging from directive to democratic and gives solid examples of applying them. A short read but an essential handbook for leading effectively in the digital and information age.