Powerful tools for facilitating teachers' professional development and optimizing school improvement efforts! Combining professional learning communities (PLCs) and action research, this step-by-step guide provides coaches, workshop leaders, and staff developers with strategies, activities, and tools to develop inquiry-oriented PLCs. The authors present essential elements of a healthy PLC, case studies of inquiry-based PLCs, and lessons learned for improving coaching practices. Sample projects and reflection prompts will help readers: • Organize, assess, and maintain high-functioning, inquiry-oriented PLCs • Facilitate the development of study questions • Enable PLC members to develop, analyze, and share research results • Lead successful renewal and reform efforts