First, Break All the Rules by Marcus Buckingham and Curt Coffman
This is the second business book I'm adding to my bookshelf series. This book has taken the business world by storm and has become required reading in most MBA schools. I include it in my collection here for one for a very important reason: it will help you stay employed during these turbulent economic times.
It's a fast read and contained within its 270 pages are some of the most profound (and counter-intuitive) secrets ever revealed about how the biggest and most successful companies in the world do business. It's based on a Gallup study of over 80,000 managers from 400 different companies and is to date the largest study of its kind. There are lessons on economics, leadership, and career management with concrete guidance on how to apply these lessons to everyday situations.
Besides the face value of increasing your business acumen, there's also a hidden benefit to this book - you will be able to recognize which companies are worth working for. Sounds easy, but the speed at which companies fold or turn over, there's no better career skill than being able to assess the caliber of the company's values, leadership, and talent. You'll never look at your manager the same way after reading this book.
Check out the complete Architect Bookshelf series for more recommendations for software architects.