Here's about as simple of a diagram as you will get. The black/white/green wires that are on the lower left corner are the power feed coming in from whatever cord you have plugged into the wall.
If you don't want heating capability then don't connect either of the wires that are on terminals 5 or 6 of the controller (and there is no need to break off the tab on the outlet either).
If you don't want cooling, then don't hook up the wires that are on terminals 7 and 8 of the controller (and there is no need to break off the tab on the outlet).