Question Can I plug it in?

Yes you can, that's what it's there for, there is another one that's somewhere above your CPU socket, that one is for your CPU cooler and the fan on that on speeds up and slows down according to your CPU's temp
 
Yes you can, that's what it's there for, there is another one that's somewhere above your CPU socket, that one is for your CPU cooler and the fan on that on speeds up and slows down according to your CPU's temp
I noticed that there's also one just slightly above my graphics card, but will that fan be able to screw on the front or back?