Short and Sweet FISH
This book is a great quick read. Not that new, first published in 1996, there is an incredible website with resources, blog, teaching aids that have built on the initial success of this book.
If new to leadership you would be good to start with this book in your toolkit. If you feel a bit overwhelmed and want to make a positive change regardless of your position this book can give you some valuable insights.
If struggling with teams and where to start this is a good place. I think mainly for the simplicity of the approach but also because of the positive nature of it's philosophy. I'd love to use more of the resources so if anyone else is keen let's talk more.