The tools should be already provided by the webhost. If you are using a payed host then you will be using a control panel like cPanel or Ensim or Plesk. These should have options for "statistics" which should then analyse your logs and produce very pretty patterns and graphs etc
The common tools that are USUALLY provided are Urchin, Webaliser and AWstats. If you cannot find them in your control panel then maybe you should ask your host if they are installed on the server. If they are not installed then you have a problem - you cannot installed them yourself without root access to the box.
The other option is to use a 3rd party analyser that places a bit of code on your page and then uses that to track visitors - the downside of this is that you can only put ONE piece of code on ONE page, so you can only track visitors on that one page - the software mentioned above will track visitors accross all your pages.