Good Teachers make Good Students

As the Curriculum Specialist overseeing 25 middle and high schools with 220 mathematics teachers, I believe that the best chance of increasing student achievement is to increase the effectiveness of teachers. To this end, I am running a Professional Development series of sessions on Effective Teaching Strategies. We will meet six times during the school year. Each time I will seek to bridge research with practice by selecting a topic (such as Formative Assessment, Explicit Instruction, and Rigorous Tasks), reading research to learn how these strategies can be most effective, and sharing this information with my teachers. (There are about 20 high school mathematics teachers and 10 high school Special Education teachers participating.)
This is something I have never done before and I am open to suggestions. Particularly, what tasks can I have the participants do during the sessions so that they are not just listening to me?