The U.S. Department of Education has issued "Frequently Asked Questions about the June 29, 2010, Dear Colleague Letter." The FAQ is "a 'significant guidance document' under the Office of Management and Budget's Final Bulletin for Agency Good Guidance Practices."
Here's an excerpt:
Specifically, some postsecondary institutions were using electronic book readers that are inaccessible to students who are blind or have low vision. As explained by the DCL, application of our long-standing nondiscrimination requirements means that schools must provide an electronic book reader (i.e., the technology that the school uses to provide educational benefits, services, or opportunities) that is fully accessible to students who are blind or have low vision; otherwise schools must provide accommodations or modifications to ensure that the benefits of their educational program are provided to these students in an equally effective and equally integrated manner.
Read more about it at "Joint 'Dear Colleague' Letter: Electronic Book Readers."