As a part of the Wallace Foundation’s Principal Pipeline Initiative, GLISI prepared a set of case studies and a web-based tools to support principals in the development of assistant principals. Through these case studies, eight principals of the Wallace Principal PLC describe how they have cultivated the leadership of their assistant principals to meet the needs of not only the individual assistant principal, but more importantly, the school improvement needs of the school. The principals created these case studies so that other principals could learn the needs, methods and outcomes that led to assistant principals who had the knowledge and confidence to increase student achievement. The accompanying web-based, electronic guide offers embedded tools, templates, and suggestions to support principals as they cultivate leadership in their teams.