The following sites will lead to resources that are useful for lessons based on Social Justice or indigenous peoples themes.

Civil Rights Museum

Teachers for Social Justice

Education for Liberation

NAACP

National Museum of Native Americans

American Indian Movement

Native Web - Resources for Indigenous museums and information related to Indigenous People 

Teaching Tolerance

Southern Poverty Law Center

Anti Defamation League 

Social Justice Resources for Teachers

Everything Martin Luther King

Howard Zinn - A Peoples History 

Indigenous Environmental Network

Social Justice Journal