Under "Memory Standard", the specs listed are: DDR3 1800(O.C.)/1600(O.C.)/1333(O.C.)/1066
What is the significance of the "O.C." for all but the 1066 speeds of RAM? Will I have to overclock my RAM & fiddle with settings to get the RAM to operate at those speeds, or will I be able to drop the RAM in without any problems? I don't have much experience with overclocking, or tweaking timings/voltages.
First: The memory standards are showing what frequencies are supported by your mobo. The significance of the "(O.C.)" is to identify that the frequencies 1800, 1600, and 1333 are overclocked frequencies.
Second: You will have to overclock your RAM to achieve these settings. Overclocking is done by manually setting the DRAM specs. You would need to set your RAM manually to 1.5V; 9-9-9-24, and 1333 MHz.
Third: Your RAM is operating at 667 MHz because the RAM speed is determined by the RAM:CPU multiplier (3.33 in your case) times the FSB. Ergo, 3.33 x 200 MHz is 667 MHz.
Fourth: If you don't manually set your RAM, the mobo/BIOS will auto set/adjust.
Note: Overclocking your RAM will also OC your CPU because they share the FSB.