Smoking causes dramatic increases in cancers of the following organs, to name just a few:

Oral cavity, including lips, tounge and gums
Esophagus (~15% 5 year survival chance)
Stomach
Pancreas (5%> 5 year survival chance)
Large intestine
Lung (5-20% 5 year survival chance)
Penis
Larynx

In addition, smokers have about a twenty-fold increase chance of developing chronic obstructive pulmonary disease, an incurable disease of the lung airways associated with significant decreases in exercise tolerance, repeated infections, irreversible fibrosis and right-sided heart failure.

Hello there........Am sick of my smoking habit as it is really having a toll on my health. I want to quit but am unable to do so...maximum I can quit is for a week but after that it becomes unbearable to stay away. Please help!!! I have browsed the net for solutions and have found sites which sell pills like chantix for quit smoking. Since the pills cost a good amount I want to know if they really work. Should I go for it or not???

I found this for you, it won't magically take away your dessire of smoking. But millions of people have done it and feel awesome now, I'm sure you can do it too. If you have any faith in God, this could give you even more motivation to quit, ask him to help you with this.
Avoid places where you will be expose to other smokers and try to hang out as less as possible with friends that also smoke (at least while you are trying to quit).