Links
By making a hyperlink descriptive and unique, you can improve its accessibility. A link should always be embedded within text and make sense out of context.
Description
Linking descriptive words helps a visitor understand what they will experience by clicking on the link.
You may be tempted to use "here" or "click here" in the text of a link. When you fill your page with "click here" links, a sighted user has to reread the surrounding text to determine which link is which.
Reimagine the same scenario for a user of a screen reader. She has listened to the whole page and now wants to visit a link she heard a while back. Her screen reader can read a list of all links on the page. Except, on your page, she hears a list like this:
- click here
- click here
- click here
Unique
Links on a single page should be unique. For example, you should not have two instances of the words "Register Now" and have them go to different locations. A visitor using a screen reader won't be able to differentiate between the two links.