Ubuntu has the buzz but from personal experience I'd recommend Madriva One 2011 esp. if you have broadband internet connected via a network card. http://www.mandriva.com/en/downloads/
Easus image backup free: Best free data backup software. Hard drive backup and recovery freeware. Hard Disk image freeware.
with this program and an external drive you can back up the entire HD or particular partitions.
What I would do:
Burn the Boot CD for Easus ToDo. Make sure your system will boot from it and you can see your HD and external drive before doing anything else. If the restore on the Boot CD can't see the drives try a different program. Another is Macrium Reflect Free: http://www.macrium.com/reflectfree.aspx
In case of disaster you have to be able to restore the image using the Boot CD.
The image back up tool is only as good as the Boot CD with the restore. If you can't see it, you can't restore it.
Use the Back up entire disk option before you start altering partitions. Be able to get back to square one if anything happens.
Then once you have Windows and Linux peacefully coexisting and booting correctly, use the back up option to make an image of the individual partitions. If Linux breaks, just restore the Linux partition. If Windows, just the Windows etc..
Both Easus and Macrium are very easy to use. There are others also.
Take a look on thefreecountry.com: Free Programmers' Resources, Free Webmasters' Resources, Free Security Resources