Also see accommodations
Accessible Assessments [NCAM] http://ncam.wgbh.org/experience_learn/educational_media/accessible-assessments
(Test) Item Writer Guidelines for Greater Accessibility [NCAM] http://ncam.wgbh.org/experience_learn/educational_media/accessible-assessments/item-writer-guidelines
New links that I find but have not yet looked at closely enough to add to my lists.
.