Great overview and head start
For aspiring leaders, who are interested in understanding either how to better lead their teams or why they're stumbling, this a great place to start.  It is an easily digested survey across a field that does not come intuitively to many leaders.  It points the way to deeper study as needed to improve understanding and performance in specific areas, based on the original ideas and in the words of thought leaders across this field of study.

Rather than trying to reinvent the wheel -- or figure these theories out for ourselves -- start with this book and jump directly to heart of your team's problems.
I like it.  It is a convenient place to keep track of what you are learning with a spark of fun.  A little more variety would be good.  I really like the large size.  A hard cover would be a nice touch