To follow-up on Josh's benefits of a web usability study posted earlier this week in Web Usability: Do you care what your customer wants?,we wanted to offer you a few resources on web usability.
To start,let's visualize the process in this Step-by-Step Usability Guide from Usability.gov.
Next,to know what your web visitors really want,The Web Usability Blog recommends that you analyze your site search to increase ROI.

Consider this possibility if your site gathers very few conversions: you may have a cluttered website. Intuitive Websites offers a free internet marketing podcast reviewing top corporate websites (like Apple.com) and sharing tips/strategies on How to Avoid a Cluttered Website. (To play the podcast: press the Play or Audio MP3 buttons at the bottom of the blog post, hidden below "Rating.")
One final resource from Web Usability is a description (without oodles of technical jargon) of Navigation Accessibility with a focus on enhancing your site for those with disabilities.
So assess your site; consider how your readers/buyers use your site. What needs to be changed?
P.S. Or we can do all that for you. Here comes a shameless plug: hire the professionals at JMG to do a web usability study and turn the study results into site enhancements.