First Among Equals: How to Manage a Group of Professionals, Patrick J. McKenna and David H. Maister. Free Press, 2002.
While targeted at group leaders in professional practices (e.g., legal firms), this book has a lot to teach coaches and managers in XP teams too. Discusses how to clarify your role and set group expectations, how to coach individuals and teams, and how to build the group for the future. (Reviewed Dec., ’02)