Back in September (http://leadership-topics.blogspot.com/2009/09/very-good-leadership-model.html) I discussed the six domain leadership model developed by professors Allan Lind and Sim Sitkins at Duke University's Fuqua school and described at http://deltaleadership.com/sixdomains.htm. Since then I've been coaching on this model and have dug some more into leadership.
A current book I'm reading is Leadership That Counts: Harnessing the Power of Leadership Coaching to Deliver Strategic Value by Dianna Anderson and Merrill Anderson. This book provides a different framework, broader in scope to some extent, as well as a good discussion on how to set up a leadership program, how to justify it, and how to assess its performance. If you are in coaching or interested in getting into coaching, this book should be in your library.
Another thing that it does is provide a time-face model of how persons being coached move through time. While the Delta Leadership model is to some extent time-specific (e.g., a leader is assessed today in six domains, puts plans in place on how to improve, and later on is re-assessed), Leadership that Counts helps a coach assess where a leader is in his/her leadership maturity and how to move him/her forward.
So, I recommend this book for your coaching library.
Side note: I used to provide links to Amazon for books. Due to new FTC rules for disclosure and changes in the Amazon Associates rules, I am no longer providing such links. If you are interested in buying a book I mention, please pick it up at your favorite merchant.