• Introduction to Web Accessibility, WebAIM
• AssistiveWare videos on computer accessibility
• Victor Tsaran: "An Introduction to Screen Readers", Yahoo!
• Karo Caran: "An Introduction to Screen Magnification Software", Yahoo!

• How to Meet WCAG 2.0, A customizable quick reference to Web Content Accessibility Guidelines 2.0 requirements (success criteria) and techniques
• WebAIM's WCAG 2.0 Checklist
• Involving Users in Evaluating Web Accessibility, pay attention to the high numbers of cautions: one should be very cautious when evaluating accessibility. It's a delicate job.

• Firebug, extension for Firefox (HTML code examination, CSS, JS and DOM)
• Web developer toolbar for Firefox
• Evaluation toolbar for IE (dedicated to accessibility)
• Evaluation toolbar for Opera (dedicated to accessibility)
• Color contrast analyser
• navigateur texte Lynx (for Windows)
• ZoomText

For instructions on how to test with a screen reader, see Testing with Screen Readers: Questions and Answers, WebAIM.

• JAWS (Windows), see also JAWS (screen reader) and Using JAWS to Evaluate Web Accessibility, WebAIM
• NVDA (Windows), see also NonVisual Desktop Access and Using NVDA to Evaluate Web Accessibility, WebAIM

• Conformance Evaluation of Web Sites for Accessibility, W3C
• Involving Users in Evaluating Web Accessibility, W3C
• Survey of Preferences of Screen Readers Users, WebAIM, where Wikipedia ranked third in the list of preferred websites.
• v:Wiki Resources/Accessibility, a check-list of accessibility criteria. Possibly outdated.