Anyone who codes static web pages or dynamic web applications must ensure that the content is accessible to individuals with disabilities, including visually and hearing impaired people. The following guidelines represent the most basic steps for improving the accessibility of websites and reflect good development standards. See Advanced tips for guidelines on more complex topics.
WebAIM maintains a series of articles on accessibility. They cover most aspects of planning, assessing, and implementing electronic accessibility. These articles are an excellent primer and reference about accessibility.
Google also offers excellent introductory web developer training in accessibility.
High level concepts for designing accessible websites
Guidelines for web developers
Enabling screenreader users to comprehend images
Structure Word documents to convert to accessible PDFs
Optimize your link descriptions for use by screen readers
Solutions for text-based menu navigation, use of CSS, and math equations
Allow readers to bypass repetitive information
Tips of optimize contrast of your websites
Help screenreader users jump through content
Good code makes for accessible design
How to control the display of content
Maintaining two sites is quadruple the work
Avoid the confusion of multiple browser windows