Set the RAM to a 1:1 ratio so it'll run at stock speed when you set the FSB to 333 from 266. That'll give you 3.0GHz. Probably going to need at least a little extra voltage for the CPU, most P35 and P45 chipsets can handle up to 400FSB with little to no increase in voltage in my experience (well Asus, Gigabyte, and DFI boards mostly in my experience).
But you may need different memory if your current Ram cannot do 700+. You need 355-356FSB for 3.2Ghz (3200 / 9 = 355.55555555). And with a 1:1 ratio being the lowest that board can go on a Ram Multiplier that puts you at DDR 710. You might find the actual memory part number and put that + Overclocking in the search bar on Google or something to see what you come up with. Most G0 Q6600's I've had the pleasure of clocking hit 3.6Ghz at around 1.35-1.45v, that requires a FSB of 400, and memory that is capable of at least DDR2 800 speeds.
Make sure to read up on your MB's bios, google reviews as most MB reviews have a detailed BIOS section for you to read and better understand what you are up against. Overclocking on your setup looks like it should be pretty easy except for your memory. If it's not capable of 700-800 DDR2 speed, then you'll need to replace it with faster memory to attain the OC you want. And with DDR2 getting more and more expensive, waiting isn't necessarily the best idea. You can probably recoup some of your losses by selling your 667 memory to someone who doesn't need faster memory. Just some food for thought, but if your current memory can hit DDR2 800 at 1.8-2.0v (or whatever it's rated for) at 5-5-5-15 or so on timings, then you should be fine.
Hope that helps or at least get's ya started. Read some of the stickies here in the Overclocking section, then do yourself a favor, research and learn more about your components.
