http://www.december.com/web/develop/design.html
http://usabilitygeek.com/14-guidelines-for-web-site-tabs-usability/
http://stackoverflow.com/questions/9310219/show-a-loading-message-for-a-magento-ajax-request
http://www.leemunroe.com/
http://tylertate.com/
http://libguides.mit.edu/content.php?pid=110460&sid=1117257
http://www.nngroup.com/
http://uxdesign.smashingmagazine.com/2011/11/08/extensive-guide-web-form-usability/
http://www.quora.com/User-Experience-Design/group_open