what plugs into the red, white, black, and yell inputs????

link to picture of what i'm talking about

http://www.sonicelectronix.com/pictu...ture_id=245783

i know what it says to plug into each, but i dont know where i find each of these things...

everything else makes sense, kind of, but i just dont understand what goes in those

 

nevermind that

the guy said there should be some wires some where in the car from the amps??? where would these be?