Help your users to gauge the relevance of the link to their current activity; provide a summary of the linked page's content.
Confirm that they have reached the right destination; use the title of the destination page as the link text.
Deep-linking is linking directly to a sub-page of a site (rather than the homepage).
The issue of deep-linking introduces a number of legal (copyright) issues. As a rule; the apparent authorship of a destination page should be preserved.