The standard modes for using IFs in a classroom are:
1. Assigning class members to an issue area or topic. Consider identifying specific questions for them to address.
2. Assigning class members to a country/geographic region. Again, specificity helps.
Most often, students will work independently or in groups on projects and share information after completing them. It is possible, however, to have students work interactively, by assigning them topics or regions, letting them begin work, and then have the interacting groups (or individuals) create a collective model run with the changes that each group proposes by topic or region. That process, although more difficult to organize, allows the class as whole to investigate the interaction of their topics or regions (and to share learning about model use).
There is a web site available in support of the educational use of IFs. You will find syllabi at that site. There are several publications on IFs, including a book structured specifically for educational use.
Donald Borock has described his classroom use of IFs in print. Borock, Donald. 1996. "Using Computer Assisted Instruction to Enhance the Understanding of Policymaking," Advances in Social Science and Computers 4, 103-127.