The web is full of excellent pages explaining Go rules.
Some of them are listed on my
Alternatives page.
If you just want some quick and dirty ideas about how to play the game, read this page. The rules I present are very simple, even simplistic, and they do not claim to be full or exhaustive, or even cover every possible weird position which may (or may not) appear on a go board within next few centuries. The purpose of this page is to get you stated, give you enough knowledge so you can go out there and start enjoying games on 9x9 board without getting into too much trouble.
More advanced issues are covevered in the Go Basics section.