Below are a few resources to help publishers and the myriad of other new, digital content creators understand the basics of how to make content born accessible. These resources highlight the challenges that images, interactivity, math equations and other complex features pose, but also demonstrate how they can be addressed.
Creating accessible documents in Microsoft Word | Information Technology
Creating accessible Word documents is very similar to creating accessible html documents, so if you know how to create one, you have a leg up on creating the other.
Create Accessible PDFs from Microsoft Word Documents: The Basics
If at all possible, create a document that is not a PDF. Making a web page accessible to people with disabilities is far easier than making a PDF accessible. Microsoft Word documents are easier to make accessible than PDFs.