Nub needs processor help

[Aus]

Cola, I have an HD Radeon 5770.

Just looked up the Q9500 and the Q6600 and from what I see, they look good. (quad core ) I still don't understand what difference the GHz makes.

Also, I don't really feel like replacing the whole motherboard because of a tight budget. But i think I could add ram ( it's easy )

But how do i check what sockets/etc my motherboard has so i can use it for quick reference for when i want to add ram/change cpu, etc.

I stil don't really know how to change the CPU and what thermal paste does ( ) so a good tutorial video or something would be helpful. All the videos on youtube were filmed by a calculator so I couldn't really see anything.