The One Minute Manager by Kenneth Blanchard, Ph.D. and Spencer Johnson, M.D.

Rather charming short story of a prospective employee learning about the value of managing people honestly.

It's all so fluffy that its lessons come across loud and clear, and I intend to dip back into this again shortly, so that I don't forget it.

That said, it is very, very simple, which is great, so long as everyone else in the world agrees with you.