Once again I find myself (I said find, not touch) agreeing with the Monkey. Very good answer Oh Simian one. I would also like to add there is a growing body of evidence that there can be some detrimental effects on the still developing brains of adolescents. The most obvious result of these effects are that you will not mature correctly and end up a 25yr old who still thinks like a 14yr old. Having not done much research in to these claims, I can't vouch for their authenticity but there is at least a smidgen of truth to them. That being said, keep your head on straight, don't be going to school or work loaded or trying to take tests or do homework. Keep things in perspective and you'll probably be ok.
And most importantly...get educated. There are more than enough ignorant turds in the world. And one more thing, DO NOT GET YOURSELF or GET SOMEONE ELSE (sorry, didn't look to see what your gender is but you get the point) PREGNANT!!! I can't stress this enough. It could easily fuck up your future far more than weed.