There should be a progam called Asus Probe on the cd that came with your mother board. You might have to click on the Utilities tab at the top when you insert the cd. If it doesn't let you see the temps. for the cpu you might have to update the bios.
One warning though when you are running asus probe and have both Cool and Quiet, and Q-fan enabled it will beep at you when the cpu fan stops. By unchecking the box beside cpu fan you can make it stopp though.
Put in your ASUS cd and click over to utilities. Then search for ASUS Probe. Install that. It will give you your fan RPM. Motherboard and CPU temp and some other information you might like. Go ASUS.com after and search for any updates. You DO NOT need to change your bios to get or use this program.
ASUS K8V Deluxe (23 degrees C) AMD Athlon 64 3000+ (25 degrees C) (OC at 2.45Ghz) 1GB PC3200 AIW ATI 9600 Pro Creative Audigy 2 Platium Antec PlusView 1000AMG Windows XP Home SP2 250 GB Western Digital 7200rpm Hard Drive 74 GB Western Digital Raptor 10,000rpm Hard Drive