Congratulations on your decision to become a computer user. Now to your question. There are over a hundred GNU/Linux distributions available, most being modifications of a few key distributions: Slackware, Debian, SUSE, or Fedora-RedHat. Slackware is the best but requires some command line work so if you are new to this world then choose another while coveting Slackware for the future. Debian is probably the king of the hill, but its documentation is downright pathetic; avoid it for now. Both SUSE and Fedora are quirky in that each employs numerous kernel (the "Linux" part of "GNU/Linux") modifications to facilitate its smooth operation overall. That said, either one (SUSE or Fedora) should be your choice. I run the full installation package of each (less their non-English files) on 20G partitions with plenty of room to spare. I'm not too fond of Mandriva for three reasons: I don't like to join clubs; I don't like to pay for software; and I sure don't want to pay to join a software club. As for Knoppix, do it now. Everyone should have a Knoppix disc at his desk.