Linus Tech has a descent video for 1st timers on OC'g Haswell on an ASUS MB which is not that much different then ASRock MB's:
https://www.youtube.com/watch?v=0CHs5_TdpXE
I been running a Sandybridge on an ASUS P8Z68V-Pro Gen3 MB OC'g an I7 2700k in Off-Set Mode for the last 4 years without incident idling at 1600 mhz peaking at 4800 mhz between .9 v max'g 1.34v under water with temps not exceeding 70C under full stress.
As Linus says: Your at the Luck of the Draw in obtaining a good OC'g CPU.
I do not recommend going over 1.5 v with Sandybridge and probably lower with Haswell as it can damage the CPU's MPC and suggest you use low voltage DDR3 sticks.
I'm running 4 X's 4 MB Sticks of Samsung MV-3V4G3D-US_DDR3 at 1866 Mhz 9-9-9-24 1T at 1.34v (hard stuff to find now).
I've have my platform stable at 5.2 Ghz at 1.5 v but why chance it for 24/7 operation when 4.8 Ghz at 1.34 v does all I want it to do (I got a good chip. One of the main reasons I paid a little extra for the i7 2700k over the 2600k as the 2700k were nothing more then binned 2600k's and would likely OC higher at lower voltages. ;o)
In my opinion Haswell is a Lap Top processor - Not a DeskTop processor. So much to be said for the future of Desk Tops from Intel for the average enthusiasts where as AMD has taken a more rugged stance. Not saying I would love an Exon 32 Core V3 but at what cost on an X platform.
I'm sure U-Tube and Forums at ASRock has great videos and Info for OC'g your platform as it's a popular OC'g combination.
Type "Overclocking the i5 3570k with ASRock Z77 Extreme3" into either Google or U-Tube search.
Example:
https://www.youtube.com/watch?v=MGaqpTNSoYs
His voltages are a way too high for Haswell and in my opinion will burn that CPU up in no time but keep in mind every CPU overclocks differently. I believe your BIOS has an Adaptive Mode option which my MB hasn't.
Haswell's are a smaller die and hotter chip with Tim under the lid Vs Solder with Sandybrige having a larger die and runs cooler at higher voltage. SB is 32 nm where as Haswel is 22 nm micro-architecture with more tics per cloc and operates with less voltage but heats up considerable more when OC'd. You need a descent PSU and I recommend and AIO Cooler such as a Corsair H110 if you intend to keep that i5 3570k above 4.2 Ghz's (Pending voltage and heat in order to keep the CPU from Thermal Throttling) for any length of time.
CPUID CPU-Z will tell you all you want to know about the CPU Performance at Idle or under load, Browsing or Crunching and CPUID Hardware Monitor Pro for Voltages, Wattage, Temps and Fans Speeds for CPU, GPU's and Storage Hardware.
I also run 2 x's AMD R9 XSPC RAZOR 290X's in CF with a designated 140x60x280 Rad in Push Pull capable of 1150 X 1500 Mhz (Stupid Micron Elpida) for Gaming and the system idles at 37C for both CPU and GPU's - Go figure. All under water and never hitting 70C with no throttling. Not too shabby for an i7 2700K with an old Z68 MB. I`ve got no reason to upgrade as of yet as I can play BF4 at 122+ fps in 1080 or 1440p.
PS: Don't forget to save your best OC's Profiles in BIOS - Have fun