I have been a supervisor for almost five years. During that time, I have read many leadership books and listened to many podcasts. The company I work for even sent me to a small seminar. All due respect to John Maxwell, but I need a field manual with tactics. Enter retired SEAL Jocko Wilinck. With Leif Babin, he wrote Extreme Ownership and The Dichotomy of Leadership. Two excellent and highly recommended books, however, not the one I'm talking about.
Jocko Willink
The Code by Jocko; Book Review
If a book has really impacted me, then I want to share it with others. Jocko's stuff just pumps me up, and it will you too.
A Ronin's Journey 