Canisius College Accessibility Support Services Old Main 317, 716 888 2485
webaim.org Institute for Disability Research, Policy, and Practice. Utah State University
Excellent resource for developing web-based content generally, with further depth on topics such as table formatting.
W3C's Guide for Accessibility World Wide Web Consortium (W3C)
Here, a good place to start is W3C's Accessibility Principles