Ok, you will need Linux, I prefer to use Kubuntu 7, but there are many flavours and you can choose from each, but to start with I suggest you use Kubuntu or Fedora. Follow this link to download the complete boot up CD for Kubuntu: http://www.kubuntu.com/download.php
and for fedora: http://www.mjmwired.net/resources/mj...ad-fedora.html
then you will need lots of tools to atart with which you can get from this site: http://www.packetstormsecurity.org
and then you will see at the top of this forum there is a sticky note with all the other cool sites. But before you get any other tools get Cain & Abel from: http://www.oxid.it
this will help you lots.