If a document requires readers to scroll off the screen, you may want to include forward and backward links at the top and bottom of the page so that users don't have to scroll to the top to get to the link for the next page. It's important to consider the needs of specialized audiences, such as those with visual disabilities. The Americans with Disabilities Act requires reasonable accommodation of people with disabilities. When designing for the Web, you should remember that these users often rely on automatic screen readers. Options for accessibility include offering a text-only version, limiting information presented only as graphic images, and ensuring that all graphics have an automatic text description of the graphic.
Many Web sites give information about usability for disabled communities.
While this information is targeted towards Web design, much of it will also apply to stand-alone projects.