This group leadership training and supervision manual is designed to teach group leadership skills to school counselors, specialists, and classroom teachers who serve as group leaders in the Adolescent Group Counseling in Schools program. The project overview describes a generic group counseling program for students in fifth through twelfth grades. The first part of the manual contains the training program outline. A rationale for group counseling in schools is provided. Therapeutic impact on the school milieu is examined, and issues to address in school counseling groups are explored. The basic elements in group leadership are described. Leadership and expectations for the group are discussed. Structuring the adolescent counseling group is addressed, including the role of the group leader. An overview of group leadership tasks is provided in order of importance. Constructing the group is discussed. Group composition, individual interviews, the parent meeting, physical setting, record keeping, and addition and termination of group members are addressed. Information is presented for conducting the first group. Maintaining control and providing protection is the next leadership function to be addressed. Facilitating the processing of thoughts and feelings is considered. Providing insight into problem behaviors, group members' behaviors, and observation guidelines for groups are discussed. Leadership style, and the effect of group behavior on leadership style are addressed. The second part of the manual provides sample materials, and the third part addresses supervision. (LLL)