Since you are new to Linux, I would recommend Mandriva or Kubuntu. Since you are switching from windoze, you should give the KDE desktop a try. It is more like windoze. You can get Kubuntu here:http://www.kubuntu.org/getkubuntu
I recently switched my brother from windoze to Kubuntu and it was pretty easy. The install process for both are pretty close and GUI based. Some distros are text based for the install. Here is a link for Ubuntu based install:http://www.dedoimedo.com/computers/install_kubuntu.html
Here is a howto for Mandriva:http://www.linuxbsdos.com/2011/08/26/mandriva-2011-installation-and-disk-partitioning-guide/
I have not read through those guides but they should help. As always, things can change but the basics are this, partition, configure and let it install. If something doesn't work right, just google for the distro and add 'install howto'. You should get plenty of links.
Don't worry about some having a 2011 stamped on them. That is just for the CD/DVD software. Once you get the install done, you upgrade to the latest, just like windoze does.
I have never installed anything Microsoft on my rigs. I have been using Linux for a good long while. It is nice to not have to worry about viruses and such. I might also add, it runs better on older systems too. My brothers rig had windoze XP on it. It was getting really slow. That was with the older OS. I put a new Linux with KDE4 on it and it still runs faster plus the software is newer too.
The only thing that needs to be addressed is modem and video cards. Sometimes you have trouble with software based modems. Also, sometimes you have to download video drivers manually and install them. They usually have a step by step guide tho. Generally, the install is the hardest part.
Welcome to Linux.