I'm working on my thesis on web accessibility, I'm supposed to be writing it up now but I can't seem to end my literature review as there are so many resources on this topic. I think the lack of one central source of necessary information and the unorganized, dated, and at times dubious information out there is part of the problem (but that discussion is for another day & likely the thesis of my thesis).
During my endless literature review (going on 4 plus months), I have weeded through a ton of web resources on the topic. I've compiled the best sources for those beginning in this topic. These sources cover the various crucial facets of the issue.
I've tried to only include information below that is current or that holds up to the test of time. The W3C (the internationally-recognized leader for web standards) recently released a new version of their web content accessibility guidelines (WCAG 2) upon which many, if not most, others base their work upon. Plus technology and coding practices change rather quickly. Therefore, a lot of information is dated and at times to the point of being inaccurate, so be careful of this when researching the topic.
A good place to start is WebAIM's broad and brief Introduction to Web Accessibility.
Then it's best to head over to the W3C site, since they are the official source of the guidelines. Their Quick Tips to Make Accessible Web Sites is a good high-level summary of the most important techniques.
What To Do
Then there is the complete Web Content Accessibility Guidelines, it's a lot to wade through but it's the best source of what specifically to do.
Webcredible's 10 Common Errors When Implementing Accessibility will also help steer you in the right direction.
To get a sense of the human, inclusive side, there's an excellent free e-Book by Shawn Lawton Henry, Just Ask: Integrating Accessibility Throughout Design.
Why To Do It
The Internet has the power to improve people's lives (as well as disable via inaccessibility). Liz Ball's article The Internet Was Made for Deafblind People outlines how the Net has profoundly improved her life.
If you use any Adobe products to build your website (eg. Dreamweaver, PDFs, Flash, ColdFusion) then head to Adobe's site for their Adobe Accessibility Resource Center.
In my opinion there is no good free accessibility testing software - they are too complicated, dated, or present too much and ambiguous information. Not to mention that there are elements software can't test (e.g. the alt text for an image that says "graph" may pass, but it's hardly helpful). WebAIM's Wave tester is probably the best. It should not be used by beginners as it can cause more harm (too confusing and thus intimidating) than good. But for those more familiar with accessibility, it can point out some things you may have missed.
Making a Case for Accessibility
Web developers, designers, producers, managers, this is directed at you - the article Why Accessibility? Because It’s Our Job! is a call to embrace accessibility as part of being a professional.
There are many benefits to making a site accessible, such as improved usability for all and enhanced search engine optimization. Trenton Moss' article How To Sell Accessibility is a good overview of the various benefits and how to frame them as a business case.
If you do go ahead with accessibility and are looking to hire help then Beware the Charlatans. Accessibility expert Geof Collis describes the problems (which I have also encountered) with firms who claim to know accessibility, Collis advises on what to look out for.
Many sites that work towards accessibility will have a page on their site with details. Despite that many of these statements overemphasize the degree of accessibility, there are pros and cons as Leona Tomlinson outlines in Are Accessibility Statements Useful?.
The question over whether accessibility is legally required in Canada depends on who you talk to. There are no express laws or policy in this regards beyond the federal government requiring all their sites to be accessible via their Common Look and Feel rules. The Ontario government is moving ahead to making web accessibility required in the near future for Ontario government sites and much later for all Ontario businesses via the Accessibility for Ontarians with Disabilities Act. As far as I know this is the only Canadian jurisdiction pursuing web accessibility as law. Tt does seem like this is the way the tide is turning in Canada and elsewhere, so complying with WCAG now might save time & effort later on.
Overall the best sources of information, news, and tools are:
bookmarks on Delicious.
And the definitive source is W3C's Web Accessibility Initiative site.
If I missed an important component or if you know of a better source, please let me know.