Use IOMeter & CrystalMark for the HDD
Use 3DMark 06 for GPU although there are quite a few others like CineBench, GPU Caps viewer, MSi Kombustor etc etc
For the Processor use Prime 95....
To monitor temps you can use HW Monitor and the asus utilities....too
You of the whole system and also individual modules for every component to be benchmarked individually.
Thankyou very much!