The purpose of this dissertation is to examine effective practices of school administrators. Specifically, what leader practices positively affect the instructional capacity of a school? Through teacher interviews, I identified practices school principals can use to assist teachers and improve instructional capacity in schools. As the leader of a school (a collection of classrooms), the building principal's influence indirectly affects student achievement and student success. Consequently, a building principal needs to acquire skills, develop practices, and implement strategies to enhance the instructional capacity of a school. Enhancing instructional capacity involves providing resources within a school that enhance teacher effectiveness and promoting the social processes that facilitate professional learning and teacher knowledge. Teachers, especially experienced teachers, are best positioned to identify the resources and processes that help them meet the needs of students. This study included data collected from teacher interviews. The focus of the interviews was teacher opinions on the practices and strategies needed for school principals to improve student achievement. Teachers identified the practices building principals must possess to enhance the instructional capacity of a school. The study analyzed the practices suggested by teachers as most effective in improving classroom instruction. The purpose was to help develop best practices for building leaders and school systems to improve the instructional capacity of schools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]