First, you need to set the overclocking mode to a manual mode instead of Auto. When you do this you should see additional choices in that bios section. In particular, you should see a new entry that allows you to increase the CPU frequency (what is also referred to as "BCLK" and "FSB."). Increasing this number is how you will make the CPU go faster. However, as your CPU speeds up you will also need to add voltage to it to support the higher speed.
You also need to lower your memory frequency in order to make some headroom for overclocking. As you speed up the CPU frequency the memory will run faster as well and will soon make the system unstable. To do this you must take the memory frequency off of Auto and enter a manual frequency. I would start with DDR2 666/667 which is the next lower frequency divider below DDR2 800.
I hope you have a good aftermarket cooler on the CPU as the stock cooler will be inadequate. What cooler are you using?
Having said all that, your motherboard is a very poor candidate for overclocking that Xeon processor. It will draw more electrical power than that inexpensive motherboard can cope with.
Yes it did. You now have an additional frequency control item: "CPU Frequency" when you choose Manual and when you choose Overclock Profile you now have "Overclock Options." Using CPU Frequency you would increase the number up from 333 by entering a custom value if you want to overclock. Using the "Overclock Options" you would choose fixed levels of overclock. Now, 5% overclock is chosen. I imagine that you would use the "+" and "-" keys to change that.
But your DRAM frequency is still on Auto. You need to take it off Auto in order to set it to a lower starting frequency. This will give it room to grow.