1st Visible sign of puberty in males is
Tanner's staging in Males
Stage I :
Testicular size < 4ml
Stage II : 
Sparse hair growth
Scrotum and testis (>4ml) enlarge
Stage III : 
Hair growth darkens
Penis grows in lenght
Stage IV :
Hair growth becomes dense and coarse
Scrotum and penis continues to grow
Growth spurt occurs
Stage V :
Hair growth extend to inner thigh
Genitalia reaches adult size
Testicular enlargement > 3ml in Stage III
Testicular enlargement > 4ml in Stage II
Growth of penis
Testicular enlargement > 3ml in Stage I