Hi there. I would say it's not that simple. What kind of website do you operate, how is it doing so far? etc...
You can put up your site at our placement review forum for advices: http://forums.digitalpoint.com/forumdisplay.php?f=72 In general, Adsense will perform if: 1) You have a great source of traffic from search engines. 2) You have blend in the ads to your content. Therefore, if you do not have any significant traffic from the search engines, you will also need advice from SEO (Search Engine Optimizers) on your site(s).