How Many Frames Per Second Do You Need? FPS, Explained

So you pretty sure you need like 400 fps to click heads, but how do you make sure you're getting the most of your hardware? This stuff can get confusing. Can someone help me make sense of all this? 

So, I found a great article from Tim Schiesser at TechSpot where he really breaks it all down for us: 

Today we’re addressing one of the most frequently asked questions we see about PC gaming: how many frames per second do you need?