http://www.usabilityprofessionals.org/ Usability Professionals’ Association is an organization for people practicing and promoting usability
http://www.acm.org/sigchi/ ACM SIGCHI – the ACM’s Special Interest Group on Computer-Human Interaction
http://www.stcsig.org/usability/ STC Usability & User Experience Community – Usability and User Experience Community of the Society for Technical Communication
http://www.hfes.org/ Human Factors and Ergonomics Society (HFES)
http://www.usability.gov Usability.gov – usability basics with focus on web usability
http://www.w3.org/WAI/eval/Overview.html Evaluating Web Sites for Accessibility – accessibility is a crucial subset of usability for people with disabilities.
This http://www.w3.org/WAI/W3C/WAI suite includes a section on involving users in testing for accessibility.
http://webdesign.about.com/od/usability/index.htm About.com’s Usability on the Web
http://www.usabilityprofessionals.org/ Usability Professionals’ Association – Organization for people practicing and promoting usability
http://jthom.best.vwh.net/usability/ James Horn’s Usability Methods Toolbox
http://www.webstyleguide.com/ The (Usable) Web Style Guide
http://jeffglover.com/ss.php Jeff Glover’s Sucky to Savvy Web Pages
User In your face User In Your Face – A free, online book about user interface design, written in installments
http://www.smileycat.com/miaow/archives/000166.html 10 tips to improve website usability testing
http://tc.eserver.org/dir/Web-Design/Usability EServer TC Library: Web Usability