Must-Have WordPress Plugins - Google Analytics for WordPress

This plugin makes it easy for you to insert your Analytics code and track custom variables as well.

Website: http://wordpress.org/extend/plugins/google-analytics-for-wordpress/

Once you've installed and activated the plugin, you have to set which Analytics profile to track:

Then you need to authenticate your account with Google Analytics and choose your other settings. You can decide whether you want the Analytics code to be inserted automatically into the header (recommended, unless you're an advanced user).

You can also track outbound clicks and downloads, plus some other advanced functions if you wish. The advanced functions allow you to track Google Adsense and other custom variables like. Here are some of the custom options:

When you log into Google Analytics, you'll see the usual stats and if you chose the Advanced Custom Variables, you'll see them under "Visitors -> Custom Variables". Now you're all set to start tracking your site. No need to manually insert codes and you're ready to go!

Other stats include audience profile, top keywords and countries.