Rahul
I remember a lot of fun was to be had with commercial OSs and tools like SiSoft Sandra. That would be a good source of ideas.
http://www.sisoftware.co.uk/index.html?dir=&location=pinformation&la...
Many of the underlying tools are available already (eg. hdparm -t, iostat, smartd, lspci, xdpyinfo, /proc, lshal) but wrapping them in a GUI would be useful for beginners.
-Cam