There is a growing body of evidence that school leadership has an impact on student outcomes second only to the influence of teachers in the classroom. Since teacher quality is the most important in-school factor in relation to student achievement, the extent to which school leaders are successful in driving teacher effectiveness is another major measure of their success as leaders. Developing human capital for their schools involves leaders in hiring quality teachers, evaluation and professional development, retention, leadership development, providing instructional leadership and, ultimately, dismissing staff members who are not performing. High-performing leaders need, however, to do more than understand theories of leadership or what makes effective teaching; they also need to be able to take effective action to achieve student outcomes and teacher effectiveness.