I don't have any experience with overclocking unlocked cpus (actually I dont have much experience with locked ones either) but I've been looking at some guides, and I had a question. Most guides suggest that you increment the multiplier by 1 starting at the default, untill you can't go higher at which point you increase the vcore. But is that necessary for a stable oc? or can you just start at a certain vcore and multiplier (eg i started at +.065V and x42) and change those values? also, what would you say the max long-term temp and vcore are for this cpu?
I agree with amuffin here, if you don't need it, don't do it. However you might be like me and just want that extra boost as you can get it.
The way I teach is always start from the ground up. I go through it the easy way honestly and run IntelBurnTest and a few monitors to tell me how hot I'm running. Remember, a HOT cpu is not a good thing. Personally my ceiling is 70C but I run a 2600k Sandy Bridge that doesn't run as hot as the 3570k Ivy Bridge at all.
I'll run a few 10-run cycles of IBT and monitor the temperatures and see how it goes. Just remember these processors set on Auto voltage while increasing the multiplier can result in an insanely high voltage so the best idea is find a happy fixed or offset voltage to run with. I believe 1.050v is a good start for the 3570k (correct me if I'm wrong here).
Either way, start climbing the clock hill and learn where the processor sits. Each chip is different and just because one guy can push +0625v at 42x doesn't mean you'll be even close to those settings.
However the most important thing about overclocking any chip on any platform is the phrase I never say enough... Read, read, and read some more. Don't just read one guide and try to ironman through.