Web:  
Department of Education Publication on Family Involvement
Educating Hispanic Students: Effective Instructional Practices
Mathematics Glossary (English/Spanish)
Mathematics TEKS Toolkit
NCISLA
(National Center for Improving Student Learning
and Achievement in Mathematics and Science)
National Council of Teachers of Mathematics
The SIOP Institute
Freelink.org Mathplus pages

Books: 
Echevarria, J., Vogt, M., and Short, D. (1998).
Making Content Comprehensible for English Learners: The SIOP Model.
Boston: Allyn and Bacon.

National Research Council. (2001).
Adding it Up: Helping Children Learn Mathematics.
Washington, D. C.: National Academy Press.

Peterson, P., Fennema, E., Carpenter, T. (1991).
"Using Children’s Mathematical Knowledge" in Teaching Advanced Skills to Educationally Disadvantaged Students: Final Report.
Washington, D.C.: U. S. Department of Education.

Carpenter, T., Fennema, E. (1999).
Children's Mathematics: Cognitively Guided Instruction.
Portsmith, NH: Heinemann.