Head Start CARES (Classroom-based Approaches and Resources for Emotion and Social Skill Promotion) is a large-scale, national research demonstration that was designed to test the effects of a one-year program aimed at improving pre-kindergarteners' social and emotional readiness for school. To facilitate the delivery of the program, teachers attended training workshops and worked with coaches throughout the school year. This report focuses on the planning and implementation of the coaching component in the Head Start CARES demonstration. Beginning with an overview of coaching as a model of professional development generally and the demonstration's coaching model in particular, the report then offers practical lessons learned about coaching social-emotional curricula in a large and complex early childhood education system. Geared toward early childhood education administrators and practitioners who are interested in adopting or modifying a coaching model, the lessons learned address the selection of the coaching model; coach hiring and training; coaching processes; coach support and supervision; and program management, data, and quality assurance. (Contains 4 tables, 1 box and 22 footnotes.)