You need to read guides specific to overclocking the ivy bridge tech before you do anything.
I recommend you have core temp, CPU-Z, and some form of stress testing software (I use prime95 large FFTs test). You should check temperatures and voltages before you screw with anything to make sure your system is running OK.
Then you need to decide if you are going to overclock using the "offset" method or not. That makes a somewhat big difference on how you approach the overclock.
With the EVO you should be able to hit 4.2-4.4 depending on how good your chip is, how hard you want to push the chip, and what voltages and temperatures you consider "safe".
Whatever you do, don't use a peice of crap overclocking program. Use BIOS only.
If you plan to do a straight overclock (non offset type) I can probably help you - please do a little reading first... It's risky to come to a forum and expect someone write you a full overclock guide. It's better than you do enough research you mostly know what you are doing, then ask a few specific questions - or post your BIOS screens after you overclock so people can help you identify any slight adjustments that might help.
1. NO DOT touch your FSB, keep it at 100, just increase multiplier and voltage.
2. You need to follow a process to find the best voltage for your specific chip. The best voltage varies from chip to chip, even if theya re the same model. For example my CPU is stable at 4.7GHz with 1.32v
3. There are a few things you need to do to get the process going. See below simplified process and link(the link is more for experienced OCers)
OK there is a guide, its not really for beginners, so it boils down to...
1. Disable all power saving adn turbo boost features and pick a load calibration, 1 being very stiff and one voltage constantly, 2 being a little more relax(easier to achieve stability), i prefer level 2.
2. Set voltage to fixed at first and drop it to 0.9v. (easier than fixed)
3. Boot into windows and run prime 95 or similar stresstest to test for stability for atleast half an hour. This will give you an idea of how sensitive your specific CPU is to voltage change.
4. Increase your voltage to 1.2v and multiplyer to 4.2GHz. Test thoroughly for an hour. Keep a close eye on temps with real temp or HWmonitor.
To go above 4.2GHz.
Increase Multiplier one at a time testing for half an hour between each bump. When stability is lost, add 0.05v and try again.
Repeat process until you reach your desired OC or unacceptable temps(drop one clock and/or Voltage) and viola you have your OC...
I've had prime95 running for a little over an hour now with no errors. Most people say to have it run for 24 hours though, because it could take over 20 hours to find an error. So far, the max temp has been 84ºC. At 100% load, it seems to range from 70ºC to 84ºC but probably averages at mid-high 70s.
Are these temps acceptable?
Now all cores are mid 60s at 100%, so I guess it varies a lot.