How can I prepare myself to become a neurosurgeon?

I am a junior in high school and plan to go on to college to major in chem or bio chem and go on to medical school and hopefully become a neurosurgeon. I am very very eager to begin learning about the science of the brain and want to prepare myself even now as a high schooler. I am currently in all advanced classes and could not be challenging myself more as far as that goes. I also will be volunteering at a hospital this summer. Any suggestions of what I should do to dip my foot into the world of neurology and prepare myself for college and medical school?