There are countless resources available on accessible web design.  Listed below are some of the guides that are available.  There are probably others not listed that are just as good, perhaps better.  Those listed below are fairly representative of what is available.

When you look at resources on accessible web design, always check for references to the Web Accessibility Initiative (WAI) guidelines.

Note: In the final resource, links will open in a new window.

Accessible Web Publishing Wizard for Microsoft Office

http://cita.rehab.uiuc.edu/software/office/overview.html

This software is available for FREE download.  According to this website:

The Web Publishing Accessibility Wizard for Microsoft ® Office offers an alternative to the native Web Publishing feature in Office. The standard Web Publishing option often creates XML based web content that can only be viewed by Microsoft Internet Explorer. Even if non-XML options are selected, users cannot easily add information that is required for accessibility. Our Accessibility Wizard simplifies the task of converting PowerPoint presentations, Word documents, and (in the future) Excel spreadsheets to accessible HTML through an easy-to-use user interface and automation of many of the details of conversion.

Macromedia Dreamweaver

http://www.macromedia.com/macromedia/accessibility/mx/dw/

According to this site:

Macromedia Dreamweaver MX 2004 provides the most complete set of tools available for building, editing, and maintaining accessible websites and web applications. Dreamweaver MX 2004 offers many improvements for users of assistive technologies, as well as for individuals seeking to create accessible web content and web applications.

Creating Accessible Macromedia Flash Content

WebAIM

http://www.webaim.org/techniques/flash/

This guide gives advice on how Flash can increase accessibility.

Accessibility White Papers

Macromedia

http://www.macromedia.com/macromedia/accessibility/whitepapers/

This is a collection of papers on using Macromedia Flash and other products to design accessible products.

Using FrontPage 2000 to create accessible content

WebAIM

http://www.webaim.org/techniques/frontpage/

FrontPage 2000, like many other web editors, can be used to create accessible web content. Many accessibility features can be added from FrontPage 2000's main interface. However, some accessibility fixes can only be done by changing the HTML code directly. Fortunately, FrontPage 2000 makes it relatively easy to edit the code. In addition, the FrontPage application has been updated so that it no longer "fixes" your HTML when you make a change to the code.