Business & Process
We built our company on Continuous Delivery principles. Here's a defining textbook on the topic. A long (but very good) read.
The Nomadic Developer is an excellent introduction to the world of consulting. Highly recommended for both those interested in working at Dev9 (to see what it's like) and those interested in using our services (to understand our business model).
A great overview of how to apply Lean principles to new business initiatives. Highly recommended reading, especially for anyone in a product management or product owner role.
An excellent overview of how to change the culture of an organization to emphasize test automation throughout the development process - including organizational change.
A comprehensive guide to the most popular agile methods, written in a light and engaging style that makes it easy for you to learn.