School leaders are critical in the lives of students and to the development of their teachers. Unfortunately, in too many instances, principals are effective in spite of--rather than because of--district conditions. To truly improve student achievement for all students across the country, well-prepared principals need the tools, support, and culture that enable them to be the best. New Leaders and the Bush Institute's Alliance to Reform Educational Leadership (AREL) launched the Conditions for Effective Leadership Project and partnered with leading researchers and practitioners to generate a comprehensive and research-based framework outlining the conditions necessary for transformational school leaders to succeed. The "Great Principals at Scale Toolkit" was designed in conjunction with the "Great Principals at Scale: Creating District Conditions that Enable All Principals to be Effective" report, which outlines and describes the essential district policies and practices that support effective leadership. The Toolkit provides resources for district leaders who want to improve conditions in their district that will enable all of their well-trained principals to be effective. Also included are a rubric and survey that district leaders can use to diagnose their current state as well as guidance on a process for identifying priority areas and strategies for improvements. [See the full report at ED556346.]