Mandriva is a free download from their website, it's got a quick installer and it comes preloaded with all the stuff you need for basic home/office productivity and internet surfing activities.
Its interface is very easy to use once you've got it set up, but its a little technical setting it up. It won't be hard for an experienced user, but for thetype of person who calls tech support to change his screen resolution, this Linux installation is probably out of his league.
http://www.mandrivalinux.com/