Links should always be in the form:
<a href="link_url_here">Link text here</a>.
Never show the reader the URL, keep it within a word or sentence.
For CERN's style guide, click here.
For CERN's style guide, click here: https://writing-guidelines.web.cern.ch
It may seem obvious, but check that the link is relevant, and always double-check links are working before publishing.