IUD questions.............?

Found this way of birth control that Looks the best to me out of everything else. I just want to hear from people that have one or have had one to know how they have done. AND what are the worst side effects? Did it cost a lot? It is painful? I have done a lot of research myself but want to hear from those who know first hand. Also.. I am 17 and have never had a kid... Is that going to make it work differently?