The 508 Compliance Resource Team Notes:
Image how hard it would be to navigate a website if you had a visual impairment, or if you couldn't see at all. Many people in today's world have visual impairments, but that doesn't mean they should not be able to access the Internet. Consider as well, if you had a physical impairment that prevented you from using your mouse, and you could only use your keyboard.
In order to have a 508 compliant website, the website must take into consideration disabled users such as those who have visual or audio handicaps, color blindness, epilepsy, or are motion impaired and format the website with those people in mind. You need to address several areas: layout, color, interactive elements such as forms and other scripts, and multimedia such as audio or video. The guidelines below on this page will give you a good idea of the things you need to consider when creating a 508 compliant website (or modifying your existing website to be 508 compliant).
Here are some tips that can assist you in making your website 508 compliant: