If you’re not using an analytics package there is a good chance that you are probably leaving a lot of money on the table,
and google’s analytics service is free so there’s really no excuse.
It does everything you need in an analytics package and will give you all the relevant ( and a few irrelevant stats ) to help you get your website performing better.
So if you arene’t currently using an analytics package, google’s free service will give you everything you need to get started making some solid business decisions about your marketing and your website.
This article courtesy of brianeisenberg.com gives you an in-depth tutorial about google’s analytics service.
Lots of good content and video tutorials ( which I like because I’m a lazy reader )
The Missing Google Analytics Manual
cheers,
Rich Paylor 
P.S. people will tell you that you need a high priced analytics package if you’re really serious about making money online,
but Google analytics will do everything you need it to for nothing. Worth trying out first of all.
