I recently purchased a Q6600 (G0 Revision) and it's a great processor so far. However, I'd like to push it to 3GHz as I've heard it's safe to do so. I have never overclocked before, but I have done some reading on it, mainly from this forum. I plan on using the settings from this video tutorial: http://www.youtube.com/watch?v=-kf_hSIpa0A
I need some advice on my RAM settings and a cheap but good cooling option.
The settings in the video are good. Don't forget to set the performance enhance to standard, if it's not set that way by default. Don't worry about the RAM timings until you get the stable OC. I don't know what your timings are, I suspect they are 5,5,5,15. The mobo will probably set them a little looser by default. Run CPU-Z and look on the SPD tab to get the timings. Since you are using value RAM you may want to set the memory multiplier to  instead of [2.40]. That will run the RAM at 667 instead of 800, but you will not notice the difference. You will probably be able to tighten the timings a little more at that speed, although that doesn't make any noticeable difference either, except in RAM benches. The Q6600 is not very sensitive to RAM speeds and timings.
Definitely get an aftermarket cooler with a backplate before you OC. I just installed a XIGMATEK HDT-S1283 with the XIGMATEK ACK-I7751 Retention Bracket (Backplate). It works well and is inexpensive. If you decide to use it, then be sure to cover the whole CPU IHS with a very thin film of TIM, because the heat pipes don't allow for proper spreading through contact. An alternative, as per Lupiron, is to run a bead down each exposed heat pipe on the base.
You should test your load temps with Prime95(use small FFTs) and Core Temp or Real Temp. Make sure you run it at least 10-15 minutes or until the temps stabilize.
Oops, one thing I forgot to address. In the video he set the Vcore to 1.275V. He has a VID of 1.3V, you will probably have a different VID.
Leave the CPU voltage on auto until you get a successful boot. Look in CPU-Z on the CPU tab and see what the voltage is. It probably won't be too high at 3G so you may not even need to touch it. If you want a lower Vcore, then after the OC is stable you can lower the Vcore in small amounts and run Prime95 to verify stability. Do this until it is unstable and then raise it to where it was last stable.
for a G0 Q6600 to run at 3Ghz you need relatively(VID/lower) to get it stable.but once you pass that you will need to increase the vcore unparallely to FSB. and you will possibly need to increase ram voltage and NB/MCH voltage as well.