Oklahoma School for the Blind recently published a free online booklet on iPad accessibility. Their booklet is designed to help teachers or parents teach their students basic iPad skills to surf with Safari, read books with iBooks, and learn text entry with Notes.
Wonder Baby: A site founded by Perkins School for the Blind dedicated to helping parents of young children with visual impairments as well as multiple disabilities. There are many links to resources and a database of shared experiences. The iPad apps section has good sets of cause and effect and music and sounds apps, as well as some articles on getting started with the accessibility options. A wealth of useful information.