Trouble with which settings is which

So I'm having trouble distinguishing which setting is the NB and SB and so fourth. Which settings is crucial for overclocking RAM and CPUs and which settings should be left on auto? For the most part, I left these settings on auto. And what are the voltages I should not pass over? Here are the settings I'm not really familiar with:

DRAM Performance Control
(G) MCH Frequency Latch

Motherboard Voltage Control
CPU Termination
CPU PLL
CPU Reference

MCH Core
MCH Reference
ICH I/O
ICH Core

DRAM Termination

We have a pretty decent guide that goes over those settings here:
http://www.overclockers.com/forums/showthread.php?t=515316