Be sure to check you carbon monoxide detector at the beginning of every heating season.
Have your chimney cleaned or inspected on an annual basis.
Remember to install a chimney cap to keep out debris, water and animals.
During cold months help create a draft by lighting the top of a rolled newspaper on fire and holding close to the throat of the chimney for about 5 minutes. This will ensure smoke goes up through the throat and does not billow out of the firebox into the house.
Get a chimney inspection if there has been any structural damage to the house or its foundation (Such as the earthquake in Baltimore during the Summer of 2011).