The graphic below gives you some great information. In addition to the items listed, I would also add:
1. Have your chimney cleaned and inspected if you are planning on using the fireplace this winter. Built up creosote can catch on fire and cause devastating loss.
2. Have you heating system serviced and make sure to change your air filters regularly.
3. Insulate your attic stairs. I have been told the energy loss for uninsulated stairs is the equivalent of leaving a window cracked open.
