The mission of the Knowles Science Teaching Foundation (KSTF), to increase the quantity of high quality high school science and mathematics teachers in United States High Schools, calls for a deeper understanding of what it takes to prepare and support successful teachers. On September 21, 2006, KSTF convened a group of 41 individuals with a broad range of perspectives and expertise to address three essential questions with regard to secondary science teacher preparation: What do we know, what do we need to find out, and what research will help us fill in the gaps? Participants were intentionally selected from a diverse cross section of the education community and included teachers, educational researchers, teacher educators, policy specialists and scientists. The 41 participants formed 12 working groups and spent two and a half days addressing the following aspects of teacher preparation: . recruitment and retention; . models of secondary science teacher preparation; . pedagogic preparation including field-based experiences, methods courses, and preparing teachers for diverse populations; . content preparation in biology, chemistry, Earth science, and physics as well as the nature of science in general; . induction; . mentoring. Each working group was tasked with synthesizing their discussions and conclusions for the entire group of conference participants and in a written document. This volume represents the final outcome of that conference; 12 chapters that reflect the work of 40 dedicated scholars and practitioners who share a deep commitment to the pursuit of excellence in the preparation of secondary science teachers.