A classic (originally published in the 30's) and a must-have, this timeless piece of work can help just about anybody get along better with others and win them over to their way of thinking. Don't have a lot of time to spare? Don't worry. The book is divided into short sections, each one devoted to a particular principle that is well illustrated with many practical examples. In this way, you can read a chapter quickly, stop and do other things you have to do if necessary, and get back to the book when you have time- all without losing continuity.
Thoroughly entertaining by using fun and interesting examples, I don't think many readers will regret checking this one out and I like to think of this book as a kind of Human Relations 101 of sorts. Also recommend The Sixty-Second Motivator
for further reading on motivational principles.