You need to match your motherboard specs very carefully with RAM.
Speed; pins; etc.
That link you posted is for a laptop. Do you have a laptop?
Also it is difficult to mix RAM. For best results you want matching sticks.
Anyway there are several scans available just to give you an idea.
Such as:
http://www.crucial.com/systemscanner/
What does it show you? I am not suggesting you get Crucial but it will give an idea of what you need.
You can use
CPU_Z under SPD to find out what you already have.