How to.
This happens to be written with the bios of a DFI mobo in mind.
The bios of your mobo may not contain the same menu of setting options as the DFI bios, but the same ideas apply to other brands too.
First you test for max CPU OC while RAM is de-tuned so that it won't effect results.
Then you reverse it, and test for max RAM OC while CPU is de-tuned so it won't effect results.
Then you make whatever tradeoffs in bios settings will help your CPU and RAM results fit together, possibly setting either RAM or CPU a little lower than their max in order to accomodate the other one, or using memory dividers, or other adjustments.
Finally you run a lot of tests to prove the stability of your results, within acceptable temperatures.
This guide helped me achieve a nice OC that I'm happy with, so I recommend it. Some of the other guides mostly focus just on RAM with scant mention of CPU OC.