n00b builder here. It's not my first one, but the first one I really want to do right. I've been looking at the CPU chart and I can't find a key that tells me what the numbers after the processor name mean.
Example: Core 2 Duo E6750 (Conroe, 2666/333, P35, 800)

Conroe obviously the name of the core
2666 Is this the processor being a 1333 (it is) x2 for Dual Core?
333 I have no idea what this is.
P35 would that be the Intel chipset of the mobo used for the test?
800 I'm assuming 800 is the RAM speed, but don't know how that translates into what I see when shopping for it.

While I'm on it, The E6750 looks like a clear winner over the Quad Core Q6600 on the charts for the gaming demos, but the Q6600 looks like it's being worked up as the CPU of choice in some of the THG articles. Why? I understand 4 v 2 cores, but everything I've read says nothings using the 4 cores so why bother? Is it more OC'able than the E6750? I noticed that the Q6600's numbers (2400/266, P35, 800) on the chart are lower than the E6750. Does that indicate that it's doing only slightly less in performance with lower speeds?

Conroe = name of the core (like you said)
2666 = the processor is running at 2666Mhz, or 2.66Ghz.
333 = FSB speed, which means FSB is running at 1333Mhz (since FSB is quad-pumped, so 333 x 4)
P35 = Intel chipset. Nvidia chipset go by 6x0 or 7x0.
800 = DDR2 RAM speed used in testing.

The reason why Q6600 is the choice of many THG user is that, it is a mid-range quad core (270 USD), and although running at 2.4Ghz stock, it can be easily overclocked to 3.0~3.2Ghz. So having a quad core that's capable of running (sometimes) faster than some dual cores definitely is a plus.

As for the number for Q6600, Q6600's FSB is slower than E6750 (266 vs. 333). However, this doesn't affect its performance much (1~2%). Therefore, you can pretty much eliminate that.

EDIT: DDR2-800 is pretty much sufficient for your use, unless you're looking at overclocking your CPU over FSB 400Mhz (which most of the time requires substantial voltage increase). So, if you're not ready to venture into moderate to heavy overclocking, DDR2-800 is plenty sufficient.

Thanks.
How is the processor running at 2666? According the specs on the E6750, it's 1333 MHz. Obviously 1333 x 2 = 2666, but where does the "x2" come from?

The 1333Mhz is its FSB speed. Since FSB is quad pumped, FSB clock is running at 333Mhz. E6750 has a mulitplier of 8, so 333Mhz x 8 = 2,666Mhz, or 2.66Ghz.

So take E6850 for example, it has a multiplier of 9, with the same FSB clock. Therefore, 333Mhz x 9 = 3.0Ghz.

There's no x2.

One thing that may help:

Usually the CPU has a rated FSB. In that case 1333. That is basically quad pumped.

1333/4=333mhz

So the CPU will have its stock multi, so it would be for the E6750 - 8.

333x8=2664mhz or 2.66ghz

So for another example:

E4400 FSB rated 800mhz:

800/4=200
200x10=2000mhz or 2ghz

The X2 is actually only used for AMD. It's the name of their processors and just denotes the Cores. Athlon 64 X2 = A dual core Athlon 64. The quad core AMD is the Phenom X4.

Intel uses the name Core 2 Duo and Core 2 Quad (2 and 4 cores respectively).