A guide and resource for clients and client organizations in an increasingly important and complex field of services, this is how the three prominent authors describe their book on the quality and performance of consulting. As experienced consultants, they have a deep understanding of the consulting forms of supervision, coaching, and organizational development, including their possibilities and limitations. After a general section on changes in organizations, they dedicate a separate chapter to each of the three consulting forms. The first part of each chapter explains the concept (goals, approaches, principles, phases, possibilities, limitations, etc.). Following this, quality criteria for consulting are listed, and the profile of good - or perhaps one should say perfect - consultants (supervisors, coaches, advisors) is defined. The references to the versatility of the demands placed on consultants make decision-makers aware of how challenging the consulting profession is. Thus, the guide and resource achieves its goal: the realization that supervision, coaching, and organizational development assignments should be entrusted to qualified and experienced consulting professionals. In conclusion: a worthwhile read for anyone who needs to approve consultations or who themselves seek supervision, coaching, or organizational development.