There is no single correct approach to curriculum design, but cooperation among district leaders, school administrators, and teachers is essential to develop and implement effective curricula. Principals play a key leadership role in promoting cooperation. Part 1, "Laying the Foundations," reviews the current knowledge base, examines the four levels of curriculum work, and explains the importance of the principal's role. Principals can offer better leadership if they remain aware of such changes as the growing importance of standards, school-based curriculum development, and changes in research on effective curricula. Curriculum development is enhanced when the state, district, school, and classroom exercise their legitimate roles collaboratively. Part 2, "Shaping State and District Curricula," explains how principals influence curricula through networking and advocacy at the state level, and direct involvement in design at the district level. Part 3, "Providing Leadership," focuses on the importance of a distinctive curriculum for each school, while ensuring effective delivery of district curriculum. Schools should review their curriculum quality goals, evaluate and revise existing programs, and commit to a learning-centered schedule. An effective curriculum must be integrated, align various curriculum types, and monitor implementation. Part 4, "Working with Teachers," explains how principals can work with teachers to make classroom curriculum operational and meaningful through yearly planning calendars, developing units of study, remedial learning, and enriching and evaluating the curriculum. Part 5, "Looking Ahead," provides numerous practical methods of implementing leadership skills. (TEJ)