Universally designed curriculum provides multiple means of representation, expression, and engagement to students with a wide range of abilities, disabilities, ethnic backgrounds, language skills, and learning styles.
Universal Design of Instruction at the University of Washington’s DO-IT site is devoted to the principles and the rationale behind Universal Design of Instruction. This page also lists other resources for further reading.
Center for Universal Design at North Carolina State University. Their site lays out general principles of Universal Design that can be applied to instruction.
AccessIT (another part of the University of Washington’s DO-IT site) “The National Center on Accessible Information Technology in Education.” Of particular interest is their Accessible University Companion Guide which has a series of mock “inaccessible” websites followed by examples of how to makes these sites more accessible to everyone.