Here's an old basic Asus A8N32-SLI Deluxe OCing guide i wrote up (i still have mine; it's my HTPC now).
First off, a few things to know
CPU speed is determined by multiplier & HTT (Hyper Transport Tunnel - akin to FSB)
CPU multi x HTT = clockspeed.
On an A64 X2 4800+, that's 12 x 200 = 2400 MHz
HT (Hyper Transport) speed (akin to system bus speed) is determined by HT multi x HTT
So normally that's 5 x 200 = 1000 MHz, or 2000 MHz (doubled pumped)
It is generally recommended to keep the HT speed around or under 1000, since performance is not decreased if it's lowered, & it will remain stable.
Running the HT speed much higher than 1000 will often cause instability.
RAM speed is more complicated.
It is based off CPU speed also.
Normally it runs at the same speed as the HTT, so usually 200 MHz (DDR400).
However, when OCing, raising the RAM above it's normal operating frequency only works to a certain point.
Therefore, one can use dividers, meaning the RAM will run at a lower speed than the HTT. On A64 (or Opteron) systems, the performance hit with running the RAM slower is
very minimal, & the resulting increased CPU speed is still much faster overall.
In many cases, this is a much more complicated number to calculate, but here's the formula anyway:
How to calculate RAM dividers:
(CPU multi x 200) / RAM divider (i.e. 166) = ___(always round this up if not whole number)
CPU multi x HTT / result of initial calculation = actual RAM speed
e.g.
OCed CPU clockspeed / result of the first calculation = actual RAM speed
one full example:
12 x 200 / 166.66 = 14.4 rounded up -> 15
12 x 220 / 15 = 176 aka DDR352
Now the good news is, if that's too confusing, you can actually skip straight ahead to the actual OCing, since this guide will lay out the basics in a simple fashion
Okay.
Everything you'll need to change is in the advanced menu.
First, go to
Advanced
Then
Chipset. Then change SB to NB Frequency to 4x, or
if you are raising the HTT above 250, then 3x.
There, you've now lowered the HT multi.
Now go to
CPU Configuration, which oddly enough, has no settings to do with the CPU

Make sure the 1T/2T Memory Timing is set to 1T,
unless you have all four RAM slots populated. In that case, set it to 2T if it's not already.
Then click on
Memory Setting & it will lead you to
Memory Configuration.
Now select
Memclock Mode > Memclock Value, which will bring up the RAM divider choices.
I'd select 166 or 183 for light OCing; you can tweak around with your RAM more later.
Also, under the Memory Configuration area, you can adjust your timings for your RAM by setting MCT Timing Mode to Manual.
You can leave everything at auto, but since often motherboard's auto settings have the RAM set to undesirable timings, you can go ahead and manually set the CAS TRCD TRP TRAS to what your RAM is rated for
as long as you know those timings.
Usually the numbers are like the following:
E.g. 2-3-2-6 = CAS - TRCD - TRP - TRAS
Leave all the other RAM settings at auto unless you really know what you are doing
There, RAM divider & timings are now set.
Now to actually get to OCing the CPU

Head to
Jumperfree Configuration
Set AI Overclocking to Manual.
Now in the CPU FSB Frequency spot, you can key in whatever HTT speed you'd like.
I'd recommend very slowly increasing this, & saving bios settings, restarting into Windows, testing for stability, & repeating.
200 to 205 then to 210, or even smaller increments, etc. Don't do anything crazy like jump to 240 till you know what the CPU is capable of.
Under DDR Vcore you can adjust the voltage for the RAM.
Leave it at auto or set to manufacturer's suggested setting.
Now set FID/VID Change to Manual.
Processor Frequency Multiplier is your CPU multi.
On an X2 4800+, this is 12. The multi can be lowered, but not raised unless you have an FX series CPU.
Leave it at your CPU's normal multi.
Now under Processor Voltage, you have CPU vcore.
Be very careful here; this can damage your CPU if not properly set.
You can leave this auto for light OCing, but i'd suggest setting it manually mainly for one reason.
On the A8N32-SLI Deluxe, the greatly hyped 8-phase power it features doesn't actually kick in until you utilize Over-Voltage CPU Vcore.
Over-Voltage CPU Vcore is roughly an additional 200mV, which means you can set the normal CPU Vcore to a lower amount & utilize the Overvoltage CPU Vcore to get the same vcore as just using the normal CPU Vcore by itself, with the benefit of 8-phase power (explained more
here)
You can see in the picture earlier it's set for 1.275V + over voltage (0.2V), which = 1.475V
I'd suggest setting it to 1.2V + over voltage enabled, which will give you 1.4V, same as stock settings.
You usually safely can raise it up to around a total ~ 1.45-1.50V later if needed for heavier OCing as long as temps keep in check, but don't worry about that for light OCing.
Leave the other over voltage settings as default (disabled).
There, now you've OCed the CPU & possibly adjusted RAM/CPU vcore.
One big warning about the Asus A8N32-SLI Deluxe:
This mobo has a well known "warmboot" issue.
Simply put, when heavily OCing, you may notice the PC will sit at a black screen after a restart or after saving settings in bios.
If this happens, turn off power, & then turn on power.
So basically, don't restart. Rather, shut down & turn on instead.
Also, if for some reason the overclocked settings are rejected by your system & turning off & then on doesn't fix things, you can always reset the CMOS, which will set everything in the bios back to defaults & allow you to get the system running again.
The jumper for this is under the bottom PCI-e 16x slot; refer to manual or Asus's website if you don't know this procedure.