Users of this I-Guide can be helped if they are at any point in the pre-implementation stage for a school bullying prevention program. The I-Guide provides information on needs assessment tools and other approaches for diagnosing bullying in a school. It can also help planners who already know that bullying is a problem in a particular school, but may need guidance on how to gain support for implementing such a program. Research and evaluations of evidence-based school bullying prevention programs are included in the I-Guide if the program stated that it directly targeted bullying, victimization, or bystander behavior and also if the program’s evaluation included measures of bullying, victimization, bystander behavior, or other related bullying measures. After providing background information on school-based bullying, the I-Guide identifies and discusses10 steps for implementing school-based bullying prevention programs. The steps pertain to starting such a program; supporting it through funding, training, and adaptation as needed; and handling unanticipated problems or setbacks while ensuring long-term sustainability of the program. The I-Guide can be accessed through this web page.