The Only Investment Guide You'll Ever Need by Andrew Tobias. What it did for me was inoculate me against all manner of foolish choices that I probably would ha

The Only Investment Guide You'll Ever Need by Andrew Tobias. What it did for me was inoculate me against all manner of foolish choices that I probably would have made during my young adulthood. It's short, entertaining and practical. The mechanics of investing have evolved considerably over the years, but the author has released frequent updates. Also most of the lessons are timeless. If I could sum up the most important point in the book, it's that in investing and finance, playing not-to-lose is unreasonably effective. Playing to win is usually a losing strategy.