Building and implementing a school master schedule is one of a school administrator's most crucial tasks. A master schedule can either create opportunity or hinder teaching students. This is particularly true in middle-level schools, many of which are using information about the learning characteristics of early adolescents to reexamine how students and staff are organized for instruction. The use of teaching teams and block-time scheduling has changed scheduling practices and increased instructional flexibility and responsiveness. This guide offers suggestions regarding the development and implementation of a master schedule, and offers discussion and models of block-time scheduling. Chapters deal with the following topics: middle-level students, scheduling issues and considerations, the flexible block-time schedule, school transition programs, staffing considerations, preparing to schedule, building a block-time schedule, refining the schedule, and opening school. Five appendices contain a scheduling timeline, a letter to staff on master planning, a chart for determining staff levels, a conflict matrix, and factors to consider in selecting a scheduling program. Where applicable, references are included at the end of each chapter. (JPT)