PROPER WEB SITE ACCESSIBILITY DESIGNING

For Web Page Testing:

A simple test to see if your site passes:
http://www.cast.org/bobby/

For Web Page Designing Information:

The W3C Web Content Authoring Guidelines are the gold standard for accessible practices:
http://www.w3.org/TR/WAI-WEBCONTENT

There is also a semi-official training curriculum at:
http://www.starlingweb.com/wai/wcag/

IBM also has published design standards (the whole project covers Web design and software design on several platforms):
http://www.ibm.com/able/guidelines/web/accessweb.html

An overview of other accessibility resources at:
http://www.dcp.ucla.edu/resources/accessibility.htm