If you smoke, you’ve probably heard that quitting is beneficial at any age. It’s good for your health, can make you feel and look better, and saves you money. But you also know, from personal experience or the experiences of friends, that quitting is hard. Take heart. Today, there are more ex-smokers than smokers in the United States. There are also more and better tools to help people quit. Each year on the third Thursday of November, the American Cancer Society sponsors the Great American Smokeout. It aims to make smokers and their loved ones more aware of the benefits of quitting and the tools available for achieving that goal. In support of the Great American Smokeout, Harvard Health Publishing is giving away free electronic copies of the Harvard Medical School Guide: How to Quit Smoking. This offer ends at midnight tonight (Nov. 21, 2013).