The Ivy Bridge cpu does not overclock as good as the Sandy Bridge so starting at a random number is not recommended unless that number does not require any added voltage. With the Ivy Bridge having a low TDP adding voltage is more problematic then normal. The i7-3770k will not get as high an overclock as say the i7-2600k because of the heat issue from adding voltage at a certain frequency.
If you set the multiplier to have 4ghz and it is completely stable after stress testing then ok you would be able to start there but be aware that overclocking is a tedious, long process that requires a lot of patience and time. Small steps and lots of stress testing will get you a stable high performance running Pc. I would set your goal to reach 4.5ghz and you should be able to get there but it will take time and many adjustments and testing. There are several stickies at the top of the overclocking section that will help you with overclocking and I suggest that you read the ones that will help you and give you the proper instructions.http://www.tomshardware.com/forum/279408-29-bridge-overclocking-guide-3770khttp://www.tomshardware.com/forum/265056-29-2600k-2500k-overclocking-guide