Again, this CPU is just not powerful enough to benefit from much overclocking.
However, if you still want to try it, here are basic steps:
1) Cooling: You are going to need better than stock cooling, especially if you want to hit more than 3.5GHz
2) Voltage: You want this to remain as LOW AS POSSIBLE. Higher voltage means more heat, which is bad. At some point you will need to bump the voltage up, but you want to keep it low.
3) Base Clock: This is the clock multiplier, expressed as something like x10
4) Front side bus (FSB): This is the actual speed at which the CPU runs. It will be expressed in MHz, such as 150MHz.
Now, I don't know what stock of your CPU is. You should download CPU-z and post a snip of the CPU at stock, so we can take a look.
For first steps, you will want to boot into your BIOS and find CPU settings. Unlock these (not unlocking BIOS, this is normally just changing from AUTO to MANUAL). Now, bump up the front side bus about 25 MHz. Save the settings, and boot into Windows normally. Now, you will need Prime95 to run for a few hours to test for stability. If there are no errors, and the temperatures are acceptable, then you can move the overclock up.
The clock multiplier can also be increased, but this might cause it to become unstable faster.
I recommend taking the FSB as high as it will go, and take note of the speed. Then do the same for the base clock. Then you will need to combine the FSB and multiplier (slowly) to find where that is stable. Once that become unstable, you can bump up the voltage a little until it is, and repeat.
You will need access to the inside of your case to remove the CMOS battery (to reset BIOS settings) in case of a major hardware failure.
Overclocking is not easy, nor is it trivial. Again, make sure you have adequate cooling for the CPU, and be ready to get errors and instability.
~Lordbob
