I am trying to follow a very important standard that I must admit I have ignored up until recently. I want to make sure that my pages are accessible to a large portion of people that have disabilities. I focus mainly on tutorials that are text and image intensive, but no video / flash or any kind of animations.

What is a checklist that I can follow to ensure that many people with disabilities can have a good experience when using my web site, and what disabilities should I be most conscious of?

I know that I can't possibly please everyone. I have gone through the W3C guidelines, however I'm not entirely sure what standards apply to me. I'm not building web applications, I'm building mostly wiki like information exchanges, blogs and the occasional forum.