As suggested by the title, the purpose of this Handbook on Restructuring and Substantial School Improvement is to provide principles for restructuring and substantially improving schools. Sponsored by the U.S. Department of Education, the Center on Innovation & Improvement (CII) engaged leading experts on restructuring and school improvement to prepare modules for this handbook to assist states, districts, and schools in establishing policies, procedures, and support to successfully restructure schools. The Handbook is organized into three sections. The topic of the Handbook's modules - restructuring with a focus on the district as the impetus for dramatic improvement - is relatively new in the nation's education history. For this reason, the module authors were selected because they are highly experienced experts in their fields and can be counted on to judiciously weigh the less than definitive evidence and to state useful guiding principles.