(2) How To Win Friends and Influence People, by Dale Carnegie
This book is not a “classic,” but should be a staple read on any professional’s reading list. Dale Carnegie had a revolutionary idea at the turn of the twentieth century: we change other people’s business behavior by changing our own behavior and listening patterns. Carnegie’s book has several solutions, ranging from writing letters that will forever change your life to making your life happier. Carnegie’s landmark text was taken from a series of lectures at Columbia University and has sold more than 15 million copies worldwide.