This report addresses the core challenges faced by leaders in the current context of high expectations and accountability, often accompanied by inconsistent or limited support. The report assumes the leadership role is based on a commitment to lead for learning; that is, to pursue a learning improvement agenda for the students in the school, the professionals who work directly with students, and the school as an organization. To that end, this report frames what it means to lead schools toward improvements in teaching and learning, who does or can exercise that leadership (including but not limited to the principal), how leaders can be equipped to lead learning communities, what conditions empower school leaders to lead in this way, and how such leadership is cultivated in individuals or school communities over time. In short, the report considers school leaders' roles and responsibilities, and the authority they need to pursue an agenda of improving teaching and learning. To accomplish this, we have turned to the most current literature, especially the most prominent studies of the last decade. Our review makes no claim at being exhaustive, but rather it focuses on major studies that have initiated new thinking and have the potential to shape practice. There are four purposes for this report: (1) Consider the roles, responsibilities, and authority of school leaders--both individuals in formal positions of authority and others who also exercise leadership--in light of the best research and theory concerning the nature and exercise of educational leadership; (2) Conceptualize roles and responsibilities of school leaders in relation to the improvement of teaching and learning, while paying attention to other dimensions of school leadership and the influence of context on leadership practice; (3) Review common practices and emerging strategies in the field and the implications and assumptions of such practices; and (4) Identify unanswered questions for action and research concerning the evolving roles and responsibilities of school leaders. This report addresses these matters with special attention to school principals, who occupy the most central and visible position in the leadership of schools, but it is noted that limiting attention to these positions alone is too narrow and, in a sense, may contribute to the "leadership problem" in schools. (Contains 3 figures, 1 table, and 8 endnotes.) [The development of this report was supported by a grant from The Wallace Foundation.]