How To Win Friends and Influence People by Dale Carnegie
This is probably the most popular book of all time in its genre and has been reviewed plenty of times before. The advice works, the anectodes were informative and sometimes humorous, and the pace was gentle. I was happy when I realized I learned much of the advice in the first few chapters on my own. The later chapters contained useful information about managing people. I am not at that part of my career where I am responsible for managing others, but if that does happen I plan on re-reading this book.