If you go to the library home page and click the link to Research Databases, you'll get a more-or-less complete list of the electronic resources available: articles, ebooks, streaming audio and video, and so on. When we adopt a resource, one of the elements we look at is accessibility. Usually the vendor will supply an ADA- / Section 504-compliance statement, and in addition we look at reviews of the resources that evaluate its accessibility.
Vendors have gotten better on this issue in recent years, and it is fairly common to see text-to-speech features in the databases. Others rely on PDF for text, allowing Acrobat Reader's text-to-speech features to work.
There have been cases where we were not satisfied with a vendor's approach to this issue and ended up not adopting the resource. Of course this is also a very challenging area, and if we were to get complaints that a resource was in fact not accessible, we would investigate them seriously.
On your other question, how can you get help creating instructional material: if you mean how can you confirm that a given library information resource is accessible, you should generally assume that it is accessible. If you have doubts, you can contact the library via Ask a Librarian (phone, email etc.) with specifics and we'll help with that. If you mean checking the accessibility of your self-produced instructional materials, e.g. documents you post on D2L, I think the best thing would be to contact Instructional Development. Right now I see they've posted some info on an upcoming MOOC addressing exactly this issue.