First, you are going to need an aftermarket heatsink.
Second, I hope you have a 600i or700i.
Except for the section on adjusting memory, that's not a bad guide.
So, let's start over. Clear the CMOS memory. That will take your board back to factory defaults.
This should be your first stop. It's a generic Core2 guide.
Core2 Overclocking Guidehttp://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide
Next stop should be a guide for your particular motherboard. Google is your friend.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Unlink the memory.
Here's where I disagree with the IGN guide. It says set the memory clock to 800 MHz. I set the memory clock to twice the FSB frequency. At an FSB of 333 MHz, your memory clock should be at 667 MHz.
That's how I got an eVGA 680i board running with an E6600 at 3.6 GHz.
Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.