Every Bios is different so try to take what people say and apply to your own bios offerings (If your bios even gives you the options, some do not.)
Ram usually defaults to what your CPU bus speed. If its 200x11 then ram is 200, if it's 240X11 then it's 240. Unless you manually tell it to run at another speed.
There should be a setting in the Bios to set your FSB speed. Some Bios will do a multible (5x,4,x,3x,etc) Some will list the corresponding frequency. (1000Mhz, 800Mhz, 600, Mhz, etc... ) Traditionally DDR400 runs 2 channels of 200 MHz. Hence 200Mhz at 5x is 1000Mhz. at 4x is 800Mhz and so on. If you've set your bus speed overclock to 240 then it would be 240Mhz at 5x = 1200Mhz (most cannont attain this speed...wont boot) at 4 x = 960 Mhz (More reasonable).
If you chose 1000Mhz, that would be the 5x FSB multiplier. 800MHz is 4x etc.
So lets say you choose to do an overclock of 240x11 = 2.64Ghz CPU. If your FSB is set to 800Mhz(4x) (Originally a 200MHz clock setting, ) then overclocked would be 240Mhz*4 = 960Mhz.
Memory would be running 2 channels of 240Mhz. or technically DDR 480 instead of just 400.
I am probably going over stuff you already know, but trying to cover basics in one post since you keep posting that you are in the dark.
Now there should be a third setting for your Dram to run it at another Frequency other than your 240Mhz. There are usually several selections from a top speed of 240Mhz downward.
Setting the Mhz of the Dram for anything less than the 240Mhz would be what everyone is calling "running a divider," I believe?
I haven't run a divider on mine yet, so I'm not too posative. I think it hurts your performance slightly, so it's preferable to keep them all running at the same speed otherwise you create a bottleneck.
But do whatever you have to in order to get the Overclock to test stable as it's better to have a stable system than something wreckless.
I'm new at this, and have been lucky enough to get it going without a divider, so didn't need to look into that yet, but hope I helped some.