Not to plug a any particular web analysis tool, but I've recently installed an app called awstats... found it easy to set up and it gives me a huge amount of information. I have to say I really like it, plus its free! It's distributed under the GNU General License (GPL). Its available in a few places, sourceforge for example. It works from the command line but also as a CGI. Oh, and its also written in Perl.

Plato