When I plug my earphones in the iPod the sound comes through both the iPod and earphones. What I want to know is how to stop it on the Ipod so that it only comes through the ear phones when they are commected

Make sure the I pod's phone port doesn't have anything in it, if there's something interfering with the signal your I pod could take that as its not connected. Check your settings too, some will give you the option of doing one or the other, but both could be active.