Do they use MS Office for work, or just simple hobby stuff? If it's work stuff - leave them alone. For hobby stuff LibreOffice is a good replacement that you can trial on Windows. As far as distros go, I don't like some of the decisions that Canonical has made with Ubuntu, but it's hard to argue with how simple, reliable, and complete it is. I don't want to run it for myself, but it's great for some people.