One of the best ways to gauge your website’s effectiveness, performance, and customer satisfaction can be found right inside the measurements that analytics reveal:

• the number of interactions
• page views
• where visitors are coming from to get to your sites
• where they go once they reach your site.

via Know your users: Web analytics tools | TechRepublic. The article reviews Google Analytics and Crazy Egg.

Also recommended is Andrew Maier’s Complete Beginner’s Guide to Analytics. It is a few years old though.