The transition from boys to men are many: voice changes, acne, hair growth in new places and genital growth. With these changes come new sensations and responsibilities.
Check the links below for more information.
Male reproductive system
http://www.kidshealth.org/teen/sexual_health/changing_body/male_repro
_p2.htmlIs my penis normal?
http://www.kidshealth.org/teen/sexual_health/guys/penis.htmlCan I get testicular cancer? How to perform a testicular exam
http://www.kidshealth.org/teen/sexual_health/guys/tse.html