Chances that you are publishing a Facebook publication link on the user timeline or to a Facebook fan page upon node creation are quite high.
The video tutorial and rules can help you greatly with that. The problem arises when you want to keep track of the changes in your node and reflect those changes in your Facebook publication. To do so you will need to store the facebook publication remote ID Facebook assigns to your publication when is posted.
The most common place to store this is in the Facebook Publication entity you created. Then the workflow is: