"Public Religion Research Institute (PRRI) is a nonprofit, nonpartisan organization dedicated to research at the intersection of religion, values, and public life. PRRI's mission is to help journalists, opinion leaders, scholars, clergy, and the general public better understand debates on public policy issues and the role of religion and values in American public life by conducting high quality public opinion surveys and qualitative research. As members of the American Association for Public Opinion Research (AAPOR), the American Political Science Association (APSA), and the American Academy of Religion (AAR), our research team follows the highest research standards of independence and academic excellence." (from the source) Comments: good source for charts/graphs etc. to use in teaching.

http://publicreligion.org/