Myself I stopped smoking 13 years ago (for good I hope) and now I am repulsed by cigarette smoke, but didn't become an anti-tobacco crusader like some did in my family. Unlike them I feel a lot of compassion for people who are trying to quit smoking. Myself I used to smoke Camel plains or French cigarettes like Gitanes and Gauloises (smelly stuff!)
I can say that the first 3 weeks were the hardest part because nicotine is a very powerful drug, more addictive than cocaine, some say. So first weeks is harder because you are dealing with the physical dependence induced in your nervous system by nicotine. I remember a class in college where I learned that the faster a substance acts on the brain, the more addictive it gets and ciggies are among the fastest-acting ones.
Then there is the fight with the psychological aspect of the addiction because inconsciously we make associations like beer/cigarette, car/cigarette, coffee/cigarettes, lunch time, sex, etc.. You need to find ways to replace the time spent on smoking by doing other activities because quitting smoking will give you lots of extra time in you day.
My quick tips:
1- Tell family/friends around that you are stopping cigarettes, so they won't be offering you some inadvertantly and avoid being tempted. I really got a lot of much-needed moral support and if I was grumpy they knew why.
2- Eat lots of fruits. That helped me to substitute the habit of having a cigarette in my mouth by something else that is good for the body and non-fattening. Since nicotine is an appetite-suppressant don't be suprised if you see yourself eat more after a while, thus fruits or veggies are a good choice.
3- When I had BIG cigarette cravings, My "break the glass in case of Fire" trick was to chop a lemon in half and bite into the fruit. Unpleasant, but it worked for me.
4- Calculate the money you spend on cigarettes in a month (or year) and take that wad of cash and spend it on something that makes you happy, like a new computer or a trip out of town. That's a nice way of reinforcing positive behavior.
If for some reason you cave in, don't blame yourself too hard. I tried to stop 3 times before being nicotine free, mostly because I was lying to myself with thoughts like "ah, just one ciggie for old times sake" (That time I relapsed after 1 year without smoking).
Alcohol is dangerous when you try to stop smoking because it loosens your resolve and can awake your cravings. I had problems when going to parties, drinking 2-3 beers and seeing people smoke around me.. Danger!
This might sound esoteric, but I went to a hypnotherapist to 'reprogram' my subconscious towards being a nicotine-free person. Your mileage may vary, but I felt it did help me to go meet someone once/twice a week for the first month.
My favorite specialist on the subject of addiction Stanton Peele, http://www.peele.net
Interesting stuff about the emerging 'business' of addiction/recovery industry among other things, good books you might want to check.
Okay, my time is up. Don't worry, the cravings go away after a while, you just have to stay focused on your decision.
Hey I did it, so anybody can!