(Definitely a noob, sorry for the ignorance.)

I'm setting up a public site with a MW wiki for a purpose similar to Wikipedia, but in my humble greed I would like to add an Amazon.com Associate link to trickle a little money in the door. This link should appear on all new pages created, in the same general-user-untouchable areas that the navigation and footer elements appear.

How do I customize the default HTML generated?

Or, failing this, is there a better Wiki for this purpose?

TIA

--doug