It’s awesome that Think Vitamin is making this particular course free. If you don’t know, Think Vitamin launched a for-pay membership service that allows access to a series of video tutorials. Think of it as Lynda.com with a laser-focus on web design. I’ve only seen a few sample videos, but they are very high quality.
Accessibility is something most web designers (myself included) need a better understanding of. The fact that Think Vitamin is making this available to everyone is definitely a nice resource to have!