Assuming the responsibility of ensuring that hundreds or thousands of students obtain the instruction and knowledge that they will need to be successful in life is a serious undertaking. Courageous school principals who accept this challenge are held responsible for providing the organization and leadership that provides the foundation for an effective teaching and learning environment in both classrooms and the school library media program. School library program guidelines provide a roadmap to best practice implementation. It is imperative that school principals commit time, funding, and understanding toward requiring best practices in their school library programs, in an effort to reap the benefits of increased student achievement. The purpose of this study was to examine public school principals' knowledge and perceptions of their school library media programs. The phenomenological research approach was utilized. Elementary and secondary public school principals in one urban school district were selected as participants for the study. Data collection consisted of semi-structured interviews with an open-ended questionnaire and document review. A qualitative thematic analysis was utilized to address the research questions. Upon review of anticipated and emergent themes, the findings revealed that elementary and secondary principals' knowledge and perceptions related to their school library media programs were aligned with national and State of Alabama guidelines in the areas of Building Collaborative Partnerships and Staffing. The findings further revealed an overall lack of alignment by elementary principals in the area of scheduling. Inconsistencies in alignment were noted in both groups relating to addressing multiple literacies, modeling an inquiry-based approach to learning and the information process, and policies, procedures, and guidelines that support equitable access to ideas and information throughout the school community. Recommendations for practice were provided for practitioners, policy makers, and academicians. These recommendations included addressing school library media guidelines and best practice in educator preparation programs and professional development, as well as increased library media specialist advocacy on school, system, and state levels. Further research is recommended through the replication of qualitative studies with teachers and school library media specialists, as well as conducting related state-wide quantitative studies with school principals, teachers, and school library media specialists. [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.]