My 14 year old son has small black hairs above his penis, is he going through puberty?

Yes. Puberty is the process of physical changes by which a child's body matures into an adult body capable of sexual reproduction to enable fertilization. On average, boys begin puberty at ages 11–12. And usually complete puberty by ages 16–17. Pubic hair often appears on a boy shortly after the genitalia begin to grow and first appears at the base of the penis.