Simple Adsense Inserter

I have seemingly successfully added the Simple Adsense Inserter plugin to my site and entered the publisher id number from Google. As I have never had Adsense prior to this do I still need to put in a new Ad Unit or do I just wait now for something to happen.
I can see the place on my sidebar where the inserter is so I assume it is fine.
my site is http://www.newcastlepetphotos.com

Thank you

http://wordpress.org/extend/plugins/simple-adsense-inserter/