How do I add a widget to my facebook fan page?

[Jon]

I have a non profit organization that I created a facebook fan page for. I also created a cause application using the facebook causes app. But how do I place the cause widget that says "Donate" on the left column of my fan page that will allow me to accept donations through my fan page?
For an example, just to go the Redcross fan page on facebook. How do I link my cause app to my fan page for my non profit organization like the red cross did?