The focus of practice for the study was to build and sustain a cohesive and consistent instructional leadership team by supporting the growth and development of assistant principals as instructional leaders. This study took place in a mid-sized, high school setting in rural Eastern North Carolina. The study aimed to develop assistant principals' skills in diagnosing ineffective classroom practices and conducting consistent evidence-based observations. This provided more equitable outcomes for the school and all students involved. In a participatory action research (PAR) design, I worked closely with the assistant principals, who served as a group of co-practitioner researchers (CPR). Collectively, we learned to utilize common, observational tools and develop our inquiry-led conversation skills with teachers. The PAR focused on the development of the assistant principals' knowledge and skills with these instructional leadership activities over the course of the 18-month study. In the study, I conducted three cycles of inquiry in which the CPR members and I made improvements aligned with the PDSA model and Community Learning Exchange (CLE) processes. The CPR group continued to work together to develop their evidence-based observation skills and co-create strategies when working with teachers. Furthermore, the CPR group focused on developing these skills together and trusted in the learning experience that they would become better instructional leaders. With the assistant principals as my unit of analysis, I determined two major findings: Cultivating Better Practices and Fostering Collective Efficacy. In using stronger practices, the administrators co-developed collective efficacy for using more effective observation and post-observation practices. The study provides a blueprint for developing collaborative leadership through community learning exchanges and for how secondary principals can effectively support assistant principals. The administrators in the study gained more knowledge and confidence in their instructional practices, developed more trust with teachers, and ultimately, provided more equitable outcomes for the students in classrooms. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]