THERE IS NO MASTER GUIDE TO OVERCLOCKING, IT IS A JOURNEY OF DISCOVERY, AND A VERY EXPENSIVE HOBBY.
CPU and Northbridge:
CPU Ratio - Multipliers, if you have a unlocked BE chip (which you do) these are you CPU multipliers. (CPU Ratio x FSB = Clock)
FSB - Front Side Bus, default is 200mhz but can be increased or decreased.
CPU/NB - Your memory controller and L3 cache are directly affected here, to balance higher clocks and memory latencies you need to adjust your CPU/NB. Default is 2000mhz but the rule of thumb is 2x or better your memory speed. ie: DDR3 1600 = 800mhz which requires at least 1600mhz but 2000mhz is good.
PS: Phenom II's love the northbridge being bumped and you will see notable performance difference here.
HTT - HyperTransport, by default 2000mhz but for overclocking to balance heat issues and stability it should operate between 1800-2200mhz.
Example: Target speed 3.8ghz
1] Start with your ratio's and find the highest multiplier stable until leaving all other presets at default if your chip is stable that would be; (raise in .5 increments until unstable)
2] you can also overclock on the FSB (raise in factors of 10 and then 5 until unstable)
Ratio - 17
FSB - 225
NOTE: do multiplier first then FSB, work down the ratio and work up the FSB.
3] The CPU/NB controller set it to 2400mhz
Voltages: Set to manual.
vCore/CPU voltage : start at 1.35v and work up or down to where it is stable, if to low it will hang up/freeze or not even boot. As a rule of thumb you want lowest possible voltage that is stable, to high you will degrade and kill the chip through thermal or it will reach the thermal wall and crash.
CPU/NB: yes it needs volts to support the quicker latency times, default is around 1.175v, as you increase your NB you need to balance it with volts, around 1.250 work up or down to find stable at lowest possible voltage. BSOD's (bluescreens) are generally a imbalance in CPU/NB frequency to volts required, thats how you know you need more voltage.
DRAM Voltage: this don't worry about to much now learn the basics before moving on to RAM overclocking, but set to whatever the manufacturers voltages are ie: 1.5v - 1.65v the only time this becomes relavent is you need to bump voltage to support faster timings.
NB voltage : 1.2v is generally enough.
Load line calibration/Vdroop: set between High and ultra (motherboard dependant) if overclocking for highest parity for power needed, you want max power all the time a drop can damage components trying to run above factory specs.
Anyways thats as basic as it can get, just remember only do one thing at a time, find the highest stable ratio, then the highest stable FSB as close to default ratio (ie: 1090T 15.5) when you get the balance in settings right move on to CPU/NB and voltages, find the lowest possible stable voltages for the clocks you are wanting to run. Then you can start tweaking RAM timings and voltages.
NOTE: Thubans clock 4-4.3ghz on good cooling solutions max, don't try push high overclocks until you understand what you are doing, Phenom II's are easy to clock but as you get higher things get complicated and voltages and temps become a serious problem, start off on lower clocks and stable I would say 3.6ghz.