I concur with Waira, but to add to it as he matures see how many and how dense the pollen sacks are. Give his stem a rub and see what scent he gives off. also, apparently hairy stems on males is a good thing. I need more info on why it is, I just head it is from a couple of folks that know way more than I do about breeding.
Some like early flowering males, some think it's a bad thing. Ultimately, it may come down to gut feeling as you gain more experience.