The Q8200 has a locked multiplier. You can't actually overclock it with the multiplier as you can the K series of processors. You physically have to change the FSB frequency to get a higher clock out of it. So basically, here's the methodology of overclocking a locked multiplier chips.
Final frequency is FSB x Multiplier = Frequency
So if you have 100mhz FSB and an 8x multiplier you get
100mhz x 8 = 800Mhz final frequency.
However, you chip is a little different as it runs off the host clock which is just like the FSB.
The actual FSB isn't in the equation but the host clock is and it's just the same method. SO what you have to do is overclock the FSB by adjusting the FSB which in turn changes that host frequency. Now each board is different and their BIOS is different so I can't tell you exactly what to change but if the board has overclocking options; it should be there.
Don't go with anything extreme and do some reading up about it. I don't have a lot of hands on overclocking experience with the C2D line other than my E8400 I had a few years back but only tinkered with it a couple times. I am going to tell you this however, don't start by changing from say 333mhz to 350mhz and expect an instant OMG stable overclock. SLOWLY increase and test the system. If it doesn't boot right and has issues; there's stability problems.
Remember, overclocking a chip can be dangerous and destroy hardware. Especially with tinkering with the FSB of a motherboard as it actually can cause more than just the CPU to become more stressed by the increased speeds. This can include the RAM, HDD Controllers, PCI and PCI-x bus, and other things that run off of the motherboards FSB. That's why I hated clocking with the C2D series. You actually had to have some good hardware to reach decent clock speeds.