Diversity is the best, decreasing barriers to to access makes everyone better off!
In Ontario, specific legislation called exists to make sure organizations are improving in this area. The government website has a surprisingly helpful link for you to do a little self-audit: http://www.mcss.gov.on.ca/en/mcss/programs/accessibility/ado.aspx
If you have more than 20 employees, you need to file a report on your organization's accessibility, we think!
CSCI's experience: As an organization with under 50 employees, our website does not have to follow Ontario's accessibility requirements. But, as we are an organization committed to accessibility, it makes sense to incorporate the standards anyways.
The standards required by Ontario law are actually simply to use the W3 international standards. So, it's good to know if you're planning on building a website anywhere according to accessibility best standards. Here is what we found online:
W3C Guidelines: http://www.w3.org/TR/WAI-WEBCONTENT/ (these are wordier and harder to understand)
Other good info: http://zvulony.ca/2010/articles/internet-law/web-accessibility/