Wait a few more weeks and
Microsoft Windows Home Server will be available(the product has just been released to manufacturing) and OEM's will be selling their versions of the servers before the end of the year.
It will do exactly what you asking and as it was designed from the start as a home user product very easy to set up.
If it is for business use, then really you need to invest in Windows Server 2003 and a decent backup system (hardware & software)!
Also
here is a video on Home server being demonstrated.