You'll need to create a Google Adsense Account
It is 100% free to apply, in fact, they pay you! You'll be given the choice of how you want your payments (ie. check, direct deposit, western union, etc) - once you earn $100, they will send you a payment the next month. This is not a overnight get rich system, Google can detect any type of fraud and you should not click the ads yourself. This can, however, become a long term money solution, as it currently does now for thousands of other webmasters. Once you do finally get your first payment from Google, it will encourage to do more, get more clicks, learn what works and what does not, learn how to earn recurring income each and every month!
Once logged in to your Adsense account, look at the top right of the page, you'll see your "Publisher ID" - copy/paste that into the field General Settings >> SHOUTJockey Media Player.