School-based management (SBM) has become a very popular movement over the past decade. The World Bank Education Team's SBM work program emerged out of a need to define the concept more clearly, review the evidence, support impact assessments in various countries, and provide some initial feedback to teams preparing education projects. During the first phase of the SBM work program, the team examined in detail the existing literature on SBM. At the same time, they identified several examples of SBM reforms that they are now supporting through ongoing impact assessments. This guide on the principles of implementing SBM has been developed as a companion piece to the two reports on "What Is School-based Management" and "What Do We Know About School-based Management" (published December, 2007). It focuses on the major issues generally faced by implementers while designing and implementing SBM programs and gives examples from a number of World Bank financed projects from around the world that have SBM components. In addition, it provides more in-depth analysis of a few country case studies where the process of decentralization of authority to the local-level has taken place over the past decades. The following are appended: (1) The School System in the Netherlands; (2) Mexico's School-based Management Program; and (3) School-based Management Reforms in Spain. (Contains 1 footnote.) [Significant contributions to this report were received from Thomas Cook, Carmen Ana Deseda, Paul Gertler, Marta Rubio-Codina, Anna Maria Sant'Anna, and Lucrecia Santibanez.)