Since any software or training materials sold to the us government must be accessible-compatible, you can search for Section 508 information as well.

https://en.wikipedia.org/wiki/Section_508_Amendment_to_the_R...

The basic stuff, like adding alt tags to images that have meaning and "skipnav", so readers can choose to skip directly to the content of a page without re-reading the navigation, are actually pretty straight forward to implement.

After you retrofit a site once, you'll find these things don't add much time as you incorporate them into the process the next time.