This guide from the American Cancer Society offers a good overview of the various approaches and tools that are available to smokers seeking to kick the habit. It also includes a list of other trustworthy organizations that can provide assistance.
The National Cancer Institute created Smokefree.gov to help reduce smoking rates in the United States, particularly among certain populations. Its tools and tips are designed to organise and enforce the process of quitting.
All U.S. states have quitlines with counselors who are trained specifically to help smokers quit. Call this number to connect directly to your state's quitline.