Fall in love with your future wife who refuses to sleep with you if you've been smoking that day.
More seriously, congrats to you for making the decision. I started when I was 12, was at nearly 2 packs a day by 20, and didn't really quit until 23 or 24.
There are many methods, any of which can be good based on your physiology and psychology. For me, it was a combination of the above mentioned external motivation, lots of Nicorette (or whatever the Walmart ripoff was), and telling everyone around me that I was trying to quit. I was lucky to have good friends who would remind me all the time if I started to light up. I would sometimes chew on cinnamon sticks to satisfy the physical fixation.
I quit four or five separate times before it "took", and even now I may allow myself a couple cigarettes every few months in the right situation (or a cigar on a special occasion). It is still hard some days, especially when I'm away from home.
Best of luck to you! Please feel free to post again with progress and for support! Having people around me on my side made the world of difference.