Sorry for being late to this thread.

You can also use some accessibility evaluation tools. I would suggest that you go here, and check the box that says "WCAG 2.0" to get some tools that check accessibility in general:

http://www.w3.org/WAI/ER/tools/

If you fix stuff that these evaluation software show you, I think your blog will be among the very well thought-out websites in terms of accessibility. WAI-ARIA is for times that your application does a lot with Javascript, such as updating a region of text, or when you start using non-semantic elements for stuff they are not meant for (for example using the i tag for an icon, or the span tag as a link, etc).

thanks for the extra information