Internet Marketing advice and tips

I currently use Google Analytics, and I want to track the return visitors from my PPC campaigns from Google Adwords & Yahoo Search Marketing. For example, when someone clicks on an ad, do they come back to my site?

I would like to know the conditions required for getting my blog an adsense account. Apart from having original content, no porn what are the other conditions to meet. The terms & conditions page contains a lot of unwanted text. Can anybody brief it out.