Web Accessibility for Casual Web Designers
Validation
Any newly created or modified web page should be validated to insure that it contains only syntactically correct HTML can CSS code and to detect likely impediments to accessibility. Checking for valid HTML and CSS is so easy that there is no excuse for not doing it. Current tools for accessibility validation can find most obvious errors, but some problems may not be flagged.
Checking for valid HTML and CSS
The World Wide Web Consortium (W3C) provides the web based W3C Markup Validation Service for checking HMTL code. W3C also supports a CSS Validation Service and a Link Checker. All three are available from the Firefox Accessibility Extension.
Checking for likely accessibility issues
One of the best tools for evaluating the accessibility of web pages is the web based WAVE service. Particularly convenient is the Firefox WAVE toolbar. Once installed, you need only visit the page to be evaluated and then click on the Errors, Features, and Alerts button on the toolbar. Some accessibility problem might be missed, but the tool does an excellent job of finding most problems and pointing to other areas of potential concern.
An accessibility evaluation using a somewhat different set of criteria can be obtained from the Firefox Accessibility Extension by selecting the Accessibility drop down on the reports button.
Vischeck provides a service that helps evaluate how web pages will look to those with various common forms of color blindness.
Finally, make sure to check the appearance and functionality of all new and modified web pages using Firefox, Safari, Chrome, and Internet Explorer.