This guide summarizes the existing research findings about how relationships can help foster social and emotional development for young adolescents. It provides examples from the field that illustrate relationship-based practices that can be applied and scaled in schools, after-school programs, and community-based settings to enhance opportunities for social and emotional learning. School and district practitioners, as well as youth development practitioners in after-school and community-based settings, can use this guide to identify practices that are best suited for their communities, as well as resources to help them apply research-based insights in their work with young adolescents.