Does your family need an extra PC?
Educator, Mac expert and Linux enthusiast Phil Shapiro explains in this YouTube video how, for less than the price of some operating systems, you can configure a useful, virus-free computer with a 23-inch LCD monitor (£100 refurbished) and WiFi wireless adapter (£10). This project is easy to do and should take about an hour.
If you need more help setting up an Ubuntu Linux computer, search for a local Linux User Group (LUG). LUG volunteers are usually more than happy to give advice. Ubuntu Forums is another great place for Ubuntu users to get information and advice. You might also want to check out PCWorld's Ubuntu Linux Easy Installation Guide.