Select the Resources tool from the Tool Menu of your site.

To the right of the folder to which you would like to add the web link, from the Actions drop-down menu, select Add Web Links (URLs).

This displays the Add Web Links (URLs) page.

Enter (or paste) the web site address (URL) and enter a name of the link.

You may also click Add Another Web Link to add additional links. (Optional)

This creates links to the web sites in the selected Resource folder.