This chapter is written as an introduction to what we sometimes called non-managerial supervision. It is written for both students training to be informal educators and for workers in the field. It will explore the principles that underlie the model of supervision used by the YMCA George Williams College in its initial training courses for informal educators. The focus will be on your experience as a student or worker who is being supervised (the supervisee), and how you can most effectively use supervision to improve your learning about your practice and therefore be more effective workers.