Research-Based Web Design and Usability Guidelines

The US Department of Health and Human Services announced a freely available research-based guide to Web site design and usability on Usability.gov. In their press release, they refer to it as "...a resource that will help government, academic, commercial and other groups involved in the creation of Web sites make decisions based on user research, not personal opinions." The document can be downloaded in PDF format as one 128 page PDF or as individual chapters. Sadly, the full document doesn't make use of links in the PDF.