Descriptive Link Text

The purpose of descriptive links is to provide users with the proper context of where clicking the link will take them. There are two main concepts to consider with descriptive links: writing link text and screen reader behavior.

Links

The purpose of each link can be determined from the link text alone. The link will describe the destination. The proper link text is probably already in your content, and it just needs to be emphasized as the link. Avoid generic terms like “here” and “read more”. Link text that begins with keywords

When links begin with nondescriptive words—such as "All about bear hibernation" or "Learn more about squirrel-proof birdhouses"—skimming is slowed and the alphabetized links list is not useful. A better approach is to use only the keywords for link text: "All about bear hibernation" and "Learn more about squirrel-proof birdhouses"

For Example

Use this: Learning what to write as proper link text can be confusing, but you can learn more by visiting Descriptive Links Accessibility.
Instead of: Learning what to write as proper link text can be confusing, but to learn more click here.

Screen Reader Behavior

Screen reader software announces the presence of a link
Screen reader users often navigate websites going from link to link, using the tab key (or shift-tab to go backward), so providing links that make sense is vitally important and necessary
Many screen readers including JAWS and VoiceOver give users the option to read just the links on the page.
Non-visual users can identify links since links are tagged and identifiable by readers
Screen reader software offers a "links list" with the available links on the page.
You should not include in links words such as "link" or "website" in the link text. Doing so would provide unnecessary redundant information so providing links that make sense is vitally important and necessary

For Example:

Imagine the following items are being read to you as screen reader software would. Which example would be easier for you to understand out of context?

link http://oregonstate.edu/accessibility/descriptivelinks
link click here
link Learn more about descriptive links

See how JAWS Reads a Full URL

"link h t t p colon slash slash oregon state dot edu slash accessibility slash descriptive links"

Resources

Oregan State's Guide to Writing Descriptive Links