Can you help me Overclock my computer (First time)

Hello im just wondering if anyone can guide me through overclocking my computer.

I would like to overclock these three components

AMD Phenom II X4 940 Black Edition Quad Core Processor AM2+ 3.0GHZ

Corsair XMS2 Dominator TWIN2X4096-8500C5D 4GB 2X2GB PC2-8500 DDR2-1066 CL5-5-5-15

Sapphire Radeon HD 4870 1GB GDDR5 PCI-E.

This is my first time so please be very clear on details

thanks in advance

And you'll want to get yourself a copy of CPU-Z and also CoreTemp

You'll be working in your motherboards BIOS setup options. Will look something like this:

thank you for answering

my motherboard is gigabyte MA790GP-UD4H and no i dont use the stock cooler, i use the zalman cnps9700nt and my case is haf 932. Installed cpu-z and core temp.

and heres how my bios looks like

I used to be an AMD fan and was good with the athlon64 x2 but I'm all Intel now but I think I can still help somewhat ....start out with everything on auto ......then start here
1. set clock ratio to manual ....and increase in small amounts like 5mhz at a time should be able to start at 220mhz safely.
2. bump your ddr2 voltage up to 2.1v or whatever the manufacture recommends.
3. F10 and save settings then boot into windows and check temps and run a stress test to see if it will be stable.
4. repeat bumping up cpu until it crashes.....then bump up vcore voltage till it becomes stable again but keep an eye on your temps and dont go past manufactures vcore ratings at least not on air cooling!
wish I could tell you more but with out seeing all bios options I can only give you that much....and I'm out of the AMD loop.