NOW IS THE TIME, CLINT!!! Quitting is hard and it only gets harder, the longer you wait. My buddy Jonny is trying to quit right now (or rather, talking about quitting immediately before asking to bum a cig) and I'm giving him hell because he is WEAK!
I used to smoke back when I was a little younger than you, really bad. I quit once with moderate success, but didn't actually stop smoking. I cut way back and told people I was quitting, but the cravings never went away. And even though I was only smoking a fraction of what I had been before, I remained a daily smoker and was still wheezing and sickly from it. After a while, 'quitting' stopped meaning much to me and I was back to smoking whenever the compulsion hit me, albeit I was a little more moderate. So, tip no. 1 from Joe; if it is at all possible, quit cold turkey. Say no and mean it. If you don't, your subconcious will get the better of you and make all kinds of excuses as to why you can smoke one cig now and still not be a "smoker." Eventually the commitment you've made will become meaningless.
When I was in high school and right about your age, I had lots of extra credits in math and english so I didn't have to take the mandatory courses in those areas my junior and senior years. So, I got out of school one period early. On Thursdays, when we only had even-numbered periods, that meant that I got out at lunch time, along with several of my friends. So somebody came up with this absurd idea to buy cheap cigars and have a 'smoking club' of sorts on Thursday afternoons. Now, I know some cigars are good and I've enjoyed a few, but these were not good cigars. I remember thinking that mine tasted of slightly spoiled deli ham and leaf mould. Anyhow, there were lots of big, forested parks around my neighborhood where we used to hang out, so on one such smoking club day we hiked out into the woods to smoke. I wasn't paying too much attention, and was inhaling my cigar bit by bit rather than just puffing on it. So, cigars done, time to go find some other trouble, we get up and start walking around and I feel REALLY woozy. I'm talking root-canal anesthesia quality woozy, only not in a good way. After about twenty minutes of hiking up and down hills with no trails, I was green as a leaf and had to lie down. I don't know how long I was down, but I think the Earth revolved around me a few dozen times before I started to feel better. Ever since then, I have had very little compunction to even obtain tobacco products, and although I'll still bum a drag off of a friend every now and again, I've yet to be compelled to smoke an entire cigarette - the very notion makes my stomach turn just a little. So, tip from Joe no. 2: vigorous exercise interspersed with cheap cigars. Negative reinforcement can work wonders.
All in all, you've made an excellent decision and I'm glad to hear that you're doing it now when most kids still think they're invincible and susceptible to no one's influence but their own. We're all backing you 120%.