HOWEVER, I would strongly urge you to look into all of your options before you do Porcelain Veneers. If your teeth are horribly discolored, porcelain veneers may be your only option but look into bonding as well. Remember, once you have veneers, there is no going back. Get more than one consultation.
Various types of veneers exist and depending on age and the problems needing corrections, some of these types may apply to a 17 year old. The biggest concern I would have is: not to have to reduce good tooth structure on one so young if a more concervative procedure exists, so I would encourage exploring all options thoroughly and see if a option exists which does not damage teeth first (ie. orthodontics and or whitening, etc). We live in a wonderful world and there are multiple of options most of the time. Visit a dentist that will give you all options. Good luck!