Question about radiology?

This is a question to radiologists, radiologist techs, or someone who is close friends with a radiologist. Google is no fun, and provides the basics, so i'd like a personal answer. What does a radiologist do exactly? I heard there are risks of excessive exposure to radiation, and it can cause trauma, or cancer? I'm 15, and i'm thinking about going towards the medical field in the future, and radiology sparked my interest. What courses are recommended? How many years of further education after highschool?