By signing in google analytics from your google account that provide you a code pase that code in to the head tag of website by thius your website be link with google analytics.
I think this is not so tough. You sign with your Google account & add the URL of your website. Then you can view the reports for visitors from different sources.
First go to google analytics.com and sign up here and follow the 4-5 simple steps here and you will be able to add your site in google analytics.
Also add your site to google webmasters tools, to find more information about the effectiveness of your keywords...