to OCF!
Well, I've never had an A8N (I prefer the A8N
32) but I've OC'ed a few s939's including my own FX-60. First off, there is no "FSB" on a socket 939 system so there's no need to worry about what it means. Some fossils out there will refer to the clock (system clock, reference clock) as the FSB but that's a misnomer. I'd like to shoot the BIOS developers that still use that term - they of all people should know better!
vCore is the CPU core voltage. Almost any abbreviation that starts with "v" is a voltage. vDIMM is the RAM voltage, for example.
OC'ing with four sticks of RAM will hold back your RAM speeds. OC'ing RAM with four unmatched sticks like yours is nearly impossible. I suggest you pick the best pair of RAM sticks you have and just use those. Chances are the increased performance from the OC will offset the total amount of RAM.
You'll need to learn your BIOS. Dig out your motherboard manual and find the BIOS section - you'll need it. If you don't have a manual you should be able to download a *.pdf version at ASUS:
http://usa.asus.com/index.aspx
For now the best thing you can do is browse through the thread below, get used to your BIOS settings and where they are, and experiment with the step-by-step outlined in that thread. It's the way I learned to OC, along with help from the good folks here at OCF, and it's the best way I've found to learn. Once you've gone through and tried a few things it's natural that you'll have questions so post back. No one figures it out for themselves the first time!
Hopefully you'll have a few results from your first experiments and we can move on to your specific system.
http://www.ocforums.com/showthread.php?t=391768
Good luck - hope to hear from you soon ...