I'd help but I am using a different 680i mobo
don't set your cpu v higher than 1.5, try setting it to 1.4 volts and your FSB to 1.2 or 1.3..
don't know what your memory is rated at so would leave that default, go into the bios under cpu options I guess and set the fsb and mem ratio to linked and synced... try to up the fsb little by little until you find a spot that is unstable and then go back and adjust some of the voltages to see if you can get anymore out of it..
I don't know anything about your bios but it shouldn't be too hard to figure out...
is your q6600 a G0? you should check out http://www.xtremesystems.com/forums
they have a good intel overclocking database that goes by motherboard and cpu... lists cpu voltage and different things that could help you out.