If you want something quick and related to Brightspace, check out the Online Accessibility Lab in the D2L Academy (accessible via the Quick Links menu that you should be able to see on this page).
Beyond that, I have heard people speak positively about the Certified Professional in Accessibility Core Competencies (CPACC) from the International Association of Accessibility Professionals. UPDATE: Sorry - realised that you posted this question ages ago, but it came up when I was looking for unanswered posts. Hope you found what you were looking for in the end.
Connect with our Known and Fixed Issue information to learn about improvements made to Brightspace.
Connect with leaders in pedagogy, accessibility, learning experience design and more
The Accessibility category serves as a single point of access to three avenues in Brightspace Community leading to the Accessibility Academy, Accessibility Library and Accessibility Discussions. These avenues offer courses and articles about accessibility to enhance accessibility knowledge and a group of accessibility enthusiasts to stay connected with.
Have questions about how to use Community? Stay tuned with updates, feedback opportunities and more for the Community here!
Connect with and ask questions on how to best use the Brightspace Product to transform the way your users learn!
Connect with product experts to learn more about tools frequently used by Brightspace Developers such as APIs and integrations!
Want to learn more about Brightspace Partners and Integrations? This is the place to be!
Stay up to date with product updates and announcements in this category.
Connect with our release information to learn about monthly improvements and updates to Brightspace.
Learn more about all the upskilling opportunities with courses and resources offered via the Brightspace Learning Center, Brightspace Guided Training and other training opportunities!
