2.6.
Adding Links
Up one level
Add a link by clicking the menu choice in the Add new... menu for a folder:

You will see the Add Link panel:

Good titles for links are important, because the titles will show up in lists of links, and because there tend to be quite a number of links held in a folder as a set. Paste the web address in the URL field or type it in. There is no preview feature here, so it is best to paste the web address from a browser window where you are viewing the target for the link.
Watch Plone 2 videos about adding a link for an email address and adding links to external and internal documents.