southern writes:  

From a techsupportalert newsletter:
If you haven't dabbled with Linux for a while you should try the latest 5.1 release of Ubuntu. It's a real step forward in both ease of installation and general usage. It's available for free download [1] as a full installation version or as a bootable live CD which includes all the free software from TheOpenCD project [2].
The live CD version is a great way to try out Linux without risking your Windows setup. It also allows you to test drive popular Open Source software products such as OpenOffice, Thunderbird, AbiWord and The Gimp which come pre-installed on the CD. Ubuntu.org will even send you free CDs containing both the full install and live CD versions by mail [3] though you do have to register first. You can even order multiple sets of CDs to give away to friends. They are truly free as Ubuntu.org wears the mailing cost as well. Now how good is that? Before installing Linux beginners should check out the introductory guide referenced in the last link below [4].
[1] http://www.ubuntulinux.org/download/
[2] http://theopencd.org
[3] http://www.ubuntu.com/download/support/documentation/faq/shipit/
[4] http://www.paulstamatiou.com/2005/10/24/how-to-ubuntu-linux-for-novices/