After the basic, generic guide, look for a 680i OC guide. The way the BIOS, particularly the memory, works is different from the other boards.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the Memory Clock (or whatever your BIOS calls it) to either Linked or Unlinked with manual memory settings to twice the FSB. . At an FSB frequency of 333 MHz FSB clock of 1333 MHz), your memory clock should be at 667 MHz. Set memory voltage to the manufacturer's recommended value.
Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.
Now you can start working with the FSB frequency.
I could push my old eVGA 680i a little past 440 MHz. But the MCP temp was over 80 C.
Thanks also to JSC, really appreciate your information. I think that Fisshy summed it up nicely..."WHOA"! I'll gradually add a better cooler to the chip, and then go into the MOBO/bIOS and explore some of the things suggested here.
Appreciate your help and time! Obviously, overclocking is new to me....