http://www.adsensedecorator.com/adsense-for-youtube-videos/
How does Google Adsense work with videos from youtube?
I have about 2,000 subscribers to my YouTube videos, and someone I know said something about using Google Adsense on youtube, how it works and what should I do first?
The only how to use Google Adsense with YouTube is to become a YouTube partner. Go to youtube.com and scroll to the bottom of the page. Click on Adsense.
How To Set Up Google AdSense Video Units Via YouTube