Leadership: Theory and Practice by Peter G. Northouse
If you are interested in any form of Leadership, this in your must-have foundational book. It begins with a historical overview of the evolution (or emergence) of leadership approached over the last century and brings the reader up-to-speed on the latest trends and practices.
Northouse details thirteen different leadership approaches, explains them in context, and then provides pros and cons for each method and how each leadership style contributes to the overall understanding of the leadership process. He also provides a lot of detailed case studies, and at the end of each chapter, there is a questionnaire you can use to measure your leadership style.
While eminently suitable as a doctoral-level textbook, Northouse’s writing style is plain and accessible for the layman. This is invariably one of the first reference books I pick up when confronting a new leadership question. I will be referencing it heavily in my upcoming series on Team Leadership. Highly recommend!