Having a site that is user friendly is not only good for the visitor its very good business sense. Its not just about achieving the highest accessibility rating you can its about making sure your site meets all of your visitors needs.

This in turn means making sure you look at the site and the user experience from the visitors perspective.

The reason accessibility is so important is because it allows any visitor regardless of their physical impediments access to your content. Many disabled and visually impaired visitors will not use a conventional browser but an audio browser or other variant that specifically meets their needs. This means that for them to access the content of a site, the information needs to be presented in a suitable way.

Technical considerations for good accessibility
Web site accessibility means allowing visitors to access the content without impediment. Guidelines are issues by bodies such as the Royal National Institute for the Blind, as well as enshrined in legislation such as the Disability Discrimination Act, which all UK organisations must now comply with. These define technical and presentation issues such as:

Sufficient contrast between text and background
Ability to re-size text
Simple HTML hyperlinks for navigation

By using more advanced programming techniques such as drop down menus and other dynamic techniques, a barrier can be placed between the visitor and the content. Not only can these techniques represent a usability issue to able bodied users they can present an impenetrable barrier to less abled visitors.

However, there are other good practice techniques such as making links meaningful rather than the ubiquitous click here as audio browsers speak the links.

Key benefits of implementing good accessibility practices
Apart from being a best of breed site and being legally compliant there are key practical benefits of implementing good web site accessibility practices:

You are allowing a greater number of people access to your products and services, after all why prevent people parting with their cash. It makes good business sense especially if your site can be more accessible than your competitors.
By making your content accessible you remove technical barriers to your content which makes it much easier to re-purpose your content to other platforms such as mobile phones, television and handheld devices

How to improve your site
Any reputable experienced web developer will be able to provide a web site accessibility audit to determine how to make your site compliant including:

improve your user experience
increase repeat visits
convert more visitors to clients and
improve search engine rankings
become legally compliant