Not sure what your experience is, but I just finished my frist build and was able to get a stable overclock at 3.5GHz pretty easily but I backed it down until I get a better motherboard and CPU Cooler. My MSI board is not known for handling X6's very well. You should be good to go with the ASrock, but you may need a better CPU cooler.
Start here and adjust:
Use whatever RAM divider gets your ram speed closest to stock specs, you can mess with overclocking this once you have you processor settled. Same goes for the HT link and NB. Be sure to disable cool & quiet and turbo core as well along with spread spectrum (If you have this option in BIOS). Download coretemp or HWmonitor for temps (I added 13° offset to coretemp as the sensors read low). You want to keep it below 62°C when testing using Prime95. If you can't, you'll have to add better cooling. That said, you really don't want it running any hotter than you can help, so better cooling is always a good idea.