Here is a quick checklist to ensure you are creating and using accessible content-

• Ensure your font choices are easy to read with sufficient contrast. 
• Screen readers rely on Headings navigate pages, so use Heading level 3 for major sections within boxes and level 4 to subdivide, etc.
• All images must feature alt text. Here is a decision tree to help you determine how to best provide alt text. SpringShrare has created guidance on best practice for alt text.
• Ensure tables are appropriately used and that they are headed and labeled 
• Use descriptive anchor text for a link. Never hyperlink "click here" and avoid full length URLs.
• Create descriptive and friendly URLs when creating a guide. For example, use https://libguides.olympic.edu/copyright rather than  https://libguides.olympic.edu/c.php?g=771075&p=5530799
• Provide information in multiple formats as needed for accessibility— accessible Word versions for poorly tagged PDFs, Captions for videos and transcripts with descriptive text, etc.