I'm 16, Balls havent dropped. No armpit hair. Very few long black hairs above penis... My penis is only about 1 1/2 - 2 inches long... About hand size when erect... Can someone tell me main sign of the start of puberty and how long till my penis grows?

If your concerned, perhaps you should see a doctor. If you can't do that, then know that there are many people who develop much later in their teens and you might be one of them. I know someone like this and he is fine, so don't worry too much

You are probably just a late developer. Don't worry. Everything will be fine. If your'e worried see your doctor.