It took me 12 years and 25 attempts to quit - and I have now been free of the weed for 6 years. Good luck - stopping is painful but worth every bit of the agony if you can just manage it!!!
Plan your approach - don't just say "i'll stop now!" or, worse still, don't be one of those new years day quitters - most have a cigarette alight well before january 6th - usually when they return to work after the break! Plan a date to stop somewhere between 7 and 10 days from now and plan how you're going to stop - are you going to have a last ritual cigarette in celebration just before you stop or are you going to wake up clean and fresh as a non-smoker?
Watch your habits closely - get in the habit of carrying a notebook. Jot down the time of day and why you think you wanted a ciggie - what triggered you to light up??? Now, underneath, think hard and jot down what you would do instead in the same circumstances next week! (you could choose between taking fifteen deep, slow controlled breaths - take a glass of water - spend two minutes doodling/drawing - use a low-dosage nicotine inhalator (plastic cigarette type thing but be careful - you have to stop using this within a few weeks - however the positive benefit is that you can socialise with smokers without smoking and without feeling like an outcast!) - or devise something yourself that you can do.
Put the money you would have spent on ciggies into a money box or jam jar every day. Buy a treat at the end of each week with the money - something you wouldn't normally have - until you feel safe just watching the money accumulate! You wouldn't believe it possible how much those little white sticks were costing you!
I was very lucky in getting support from a medical student in his early twenties (st george's hospital medical school in tooting, london has on-going research into nicotine addiction). The one piece of advice he gave which really stands out and really worked was this........
"when you're at the end of your tether and you're about to walk into a sshop and buy a pack of cigarettes or you're in a pub and about to ask a friend to give you a human, wait!!! Say to yourself "i'll see how I feel in twenty minutes!"
believe it or not, the strong cravings have usually subsided well before the twenty minutes is up!!! Your mind becomes stronger and you think to yourself "i've lasted x (hours) or (days), do I really want to waste all the effort and have to start this all over again!" the brain really can win!!!
Remember - if you do give in and take up the coffin nails again, try to think about what went wrong and what you would do differently next time. Then, plan to stop again!!!
You can do it!!! Good luck!!!
Ps - if you are a regular smoker - 10 a day or more - be prepared for some nasties. As your body rids itself of the poisons (usually 7 - 10 days after quitting) you will probably develop some of the following - a cough, wheezing, flu-like lethargic feelings, headache etc - oh, and maybe even spots! Your brain (cos nicotine is very clever) will try to tell you that you feel dreadful and you'll feel better if only you smoke again! Remember - this is a temporary phase that only lasts between 5 and 7 days and once you're over this hurdle, you will really start noticing your senses of smell and taste returning!