The MVP3G2 is a great overclocker board for SS7....
To overclock to 500 MHz, set the Easy Setting Dual Jumpers (ESDJ) to 100 MHz and 5x. If you can't get into windows, (you most likely will not be able to) step the vcore voltage on the blue dip switch up in small increments (your default is 2.2volts, I think). Try 2.3, 2.4, 2.5 etc until you can get into windows and run stably. Make sure and install the Epox USDM so you can monitor your temps. The highest I recommend you letting your CPU get is about 48 degrees c. it should idle around 39 or 40 hopefully. if it's hotter, try overclocking less with less voltage.
SickBoy