I just discovered that Sarah Horton, one of the writers of the “Web Style Guide”:www.webstyleguide.com/ has published a book on designing usable web sites — Access by Design.
Even better, the “book is available online for free”:universalusability.com/access_by_design/ in the form of a very usable web site.
bq. In this book, we primarily address universal usability at the functional layer, focusing on the challenges of designing pages that are accessible and usable on different devices by diverse users. We concentrate on the functional layer because, without it, the other layers are irrelevant. An intuitive interface and informative content are useless if the basic functions of a site donâ€™t work. Like a car that doesnâ€™t start, a Web site that does not function is of no value to the user.
Excellent stuff and a valuable resource for dealing with the misconceptions of clients and stakeholders.