Leadership remains an elusive, yet critical, component of a program's effectiveness. While most would suggest that leadership is easily recognized, this too often means that "managers" are simply supporting people's particular interests and priorities. There are many theories and models of leadership. Most people have probably personally witnessed many of them. The author provides some of the more common theories (taken down to their bare essence) that relate to the role of a school librarian. Just as there are many theories and models of leadership, so too there are many definitions of leadership. A definition that would be accepted by a majority of theorists and researchers, according to Martin Chemers, is that "leadership is a process of social influence in which one person is able to enlist the aid and support of others in the accomplishment of a common task." The common task for the school librarian, then, is to develop this process of social influence through which colleagues become committed to collaboration and instructional partnerships in order to enhance student learning. The author describes what leadership is about and discusses four core competencies of leaders: (1) managing attention; (2) managing meaning; (3) managing trust; and (4) managing oneself.