Four dimensions that must be present for a group to function effectively are elaborated in this guide: (1) commitment of members to a common purpose; (2) leadership that facilitates organization and structuring to accomplish these purposes; (3) open communication among members; and (4) a climate of acceptance and trust. Defining a group as any number of people who are thought of together and who are jointly in pursuit of a common goal, the author's observations are applicable to any context, but are directed more specifically toward school and student groups. He outlines four stages of group development ("groping, griping, grasping, and grouping"), discusses different leadership styles and their impact on group development and behavior, describes group decision-making processes, deals briefly with handling group conflict, and discusses some of the ways in which groups meet members' needs. (Author/DS)