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.
This rich collection of editorial articles about smoking and smoking cessation is an excellent starting point to understand all the aspects related to the addiction and figure out the path to defeating it.
Operated in conjunction with Boston University School of Public Health, this online community offers a free quit smoking support program and a wealth of related information and resources.