The guide discusses the early warning signs that relate to violence and other troubling behavior, as well as the action steps that school communities can take to prevent violence and other troubling behaviors, to intervene and get help for troubled children, and to respond to school violence when it occurs. The introductory section describes the rationale for the guide and suggests how it can be used by school communities to develop a plan of action. The second section describes characteristics of schools that support prevention, appropriate intervention, and effective crisis response. A third section presents early warning signs, imminent warning signs, and the principles that ensure these signs will not be misinterpreted; it concludes with a brief description of using the early warning signs to shape intervention practices. This is followed by a section that presents research-based and expert-based principles that should provide the foundation for all intervention development. Other sections offer suggestions for developing a prevention and response plan and describe what to do when intervening during a crisis to ensure safety and respond appropriately in the aftermath of crisis. This guide is not intended as a comprehensive prevention, intervention, and response plan; rather, it provides reliable and practical information on what school communities can do to be prepared and to reduce the likelihood of violence.