The easiest way to measure how much energy your home is using is to monitor how much individual outlets are using and unplug the energy suckers. These tools are called Smart Plugs or Smart Power Strips. You can plug one into an outlet, and then plug your device or appliance into it. It will monitor the amount of energy that item is using and you can shut off power supply when you don't need it. Options include the Kill-A-Watt, GreenSwitch, and, a bit more advanced, the Wattson.