Google Analytics is a great tool to monitor traffic for your site and from thereon you can produce and make changes accordingly as per the requirement of your site..
I HIGHLY recommend you NOT use analytics, ESPECIALLY if you are running Adsense! Google tracks your traffic and you are MUCH more likely to get your account banned over the most simple slip up!
I'm using it now and it is useful although I've found similar information through other sites. If I use it on a word press site it only places it in the header via plug in or I can use the editor, so not sure if it'll check every page?
My favorite analytics program is Piwik. It is, in my opinion much better than google analytics and installs on your own server so you can keep your data.