This guide/toolkit is designed as a resource aid for those in schools and communities who are concerned about sustaining valuable initiatives and innovations. The focus is on sustaining valued functions and collaborations. A particular emphasis is on efforts designed to enhance how schools address barriers to learning and teaching. The material is oriented to the idea that the essence of sustainability is making systemic changes. This guide/toolkit is divided into two parts. Part I begins with an overview of what sustainability means. It is suggested that not everything is worth maintaining and that what is maintained should be fully integrated into the fabric of existing support programs and services designed to enhance the outcomes for children, youth, and communities. Section 2 of Part I includes a set of tools and aids for sustainability -- with an emphasis on processes that will mobilize partners and develop effective mechanisms for system change. In the third section of Part I, the focus is on evaluating sustainability efforts. Discussed is the necessity of formulating an evaluation action plan, adopting specific benchmarks for monitoring progress, and specifying and measuring both immediate and longer-term indicators that functions are sustained. Part II stresses that the likelihood of sustaining many valued functions and school-community connections is enhanced by connecting the work with educational reforms and school improvement planning. Section 1 outlines basic frameworks to help guide efforts to integrate with education reforms. Sections 2 and 3 of Part II reframes sustainability as an opportunity to enhance intervention and collaboration for addressing barriers to student learning and promoting healthy development. The emphasis is on playing catalytic, planning, and follow-through roles in generating the type of systemic changes that sustain and enhance functions valued by the school and community. This includes a focus on policy, collaborative infrastructure, and capacity building. The aim, over time, is to improve outcomes for all children and youth by moving initiatives for addressing barriers to student learning and promoting healthy development from the margins into the mainstream of the school and community culture. Finally, appendices and a list of references and resources drawn from a variety of sources provide additional guidance and tools and cover topics such as developing standards and expanding the accountability framework, social marketing, and enhancing working relationships. (Contains 12 figures, 10 exhibits, 2 tables, and 19 resource aids.)