I don't really have any idea what i'm doing about overclocking my cpu. I have been using nTune to overclock my graphics cards and it seems pretty easy. However, whenever I try to overclock my cpu my computer freezes up. Heres my list of hardware...

780i Motherboard
2 x 8800GT
OCZ SLI-Ready Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
Q9450
Vista Ultimate 64bit
PC Power & Cooling S75QB 750W

I know my multiplier is locked at 8x for my q9450, so i try raising my fsb on nTune but it just freezes. I don't know if stuff is getting the right voltage. If someone could tell me what voltages I need to change for all my hardware it would be much appreciated.
Also, I scored 14350 on 3dMark06, I think that's a little low for my system. Thoughts?

First of all, raise your FSB through your BIOS, not some application. What do you want to overclock your CPU to? the Q9450 has an FSB wall of 450, I actually would recommend even less. 425 will get you a almost stable 3.4Ghz, you will need to change Vcore, maybe even some NB/SB voltages.