You will need either a blank DVD or a USB drive you can erase. Head over to ubuntu.com and download it - huge file, will take a VERY long time. There are instructions on the site on how to make a bootable DVD or USB stick and make it work - should be pretty basic.

When you boot from the DVD/USB, make sure you "Try Ubuntu without installing" first, since installing will overwrite Windows permanently! (Yes, this is not technically true, but I'm trying to make this as easy as possible)

Make sure most basic things work - you should be able to open firefox and browse bitcoin talk at least. If you're satisfied it will work, go ahead and install. It'll take about 20 minutes.

If you need tech support for it, you can always write me (or BtcBoss, I would imagine). Just know what you're getting into before you do it!

Also, my condolences.