This plugin adds a box on the Write/Edit page where links associated with the post can be entered. There is not limit to how many links can be added to a post – simply click ‘Add a new link’ to add more.
Each link has a url and a title, which forms the actual link. An optional description can be added, which will appear underneath the link in the template.
Please see http://labs.dagensskiva.com/plugins/post-links/ for more information on how to use this plugin.