Set CPU Frequency to 334 right away giving you an Overclock of 3.00 Ghz. (3.006 if you really care)
Use StressCPU2 for stress testing. Give it 30 minutes to 2 hours for a quick test, if no errors, blue screens or restarts it means your stable.
You will also want to get a Temp monitering program Like Coretemp or everest. If load Temp is under 60C your good.. (For example when I was @ 3.41 Ghz My load temp on StressCPU2 never exceded 54C)
If it does restart you will have to up Vcore one notch, then more testing, continue upping Vcore untill it does not restart or error.
Thats an extremely standard OC for an E6600, 3 Ghz right away, many people don't even have to change Voltages.
You should also Set MCH Voltage and FSB Voltage to + 0.1 Right away..
Heres I guide, I suggest you follow it. Until you have a problem you can't figure out then you can post again.
Core2Duo Overclocking Guide v1.1
Only Reason I am Still on 3.204 Ghz is because SMP Folding is Buggy at higher clocks. I have gotten to 3.41 Ghz Before..
You shouldn't have to change the RAM timmings until 3.6 Ghz. Assuming you have the Same RAM as Me, which it looks like you do.