Block scheduling and intensive or extended-time scheduling have been appearing in high schools across the United States. This guidebook is designed to help each school find the best route to achieve this organizational change. The book's premise is that structural change in schools is not sufficient to create meaningful educational improvement. Change at the individual level must accompany structural change. The guidebook draws on the authors' experiences with 5 schools and 6 school districts, and represents the concerns of 210 teachers. Chapter 1 relates several educational advantages of intensive time scheduling. Chapter 2 revolves around issues of preparing for the change to block scheduling and provides examples of change management. Examples of leadership traits that have either enhanced or obstructed the implementation of block scheduling are provided in chapter 3. Chapter 4 suggests ways to reduce polarization among members of the school community when block scheduling is considered for adoption. Chapter 5 illustrates block scheduling as a tool of time and responds to concerns of those affected by block scheduling. Chapters 6 and 7 offer suggestions for restructuring the curriculum and designing courses of study. Chapter 8 identifies teachers' common concerns related to specific disciplines and provides examples of typical 90-minute classes. Methods for evaluating the curriculum, teacher instruction, student achievement, and student/teacher attitudes are described in chapter 9. Chapter 10 explores roadblocks to implementation, including collective-bargaining agreements, resource allocation for staff development, transfer students, substitute teachers, and myths. Chapter 11 offers suggestions for enhancing block scheduling and encourages teachers and administrators to continue the cycle of planning and staff development. The appendix contains sample student-, teacher-, and parent-attitude questionnaires. An index is included. (Contains 19 references). (LMI)