Differentiated Instruction:

 

Differentiated Classrooms by the Partnership for Learning:
http://www.partnershipforlearning.org/article.asp?ArticleID=256

Differentiated Education by the Partnership for Learning:
http://www.partnershipforlearning.org/category.asp?CategoryID=6

Differentiating Curriculum for Gifted Learners:
http://www.partnershipforlearning.org/article.asp?ArticleID=160

How to Differentiate Instruction:
http://www.teach-nology.com/tutorials/teaching/differentiate/planning/

National Center for Assessing the General Curriculum: 
http://www.cast.org/ncac/index.cfm?i=2876

Teaching in Mixed Ability Classrooms:  Wisconsin Education Association:
http://www.weac.org/kids/1998-99/march99/differ.htm