Don't over think it, would be my advice. I have two girls and it has become increasingly evident to me just how much pressure there is on them to be certain ways simply because they are girls. To counter this, I've tried to mind what I say and do from day 1, to show them men and women are just people and choose to live their lives in the way they see fit not based on gender. The message has to be adjusted to their age, of course, but the older they get the deeper our conversation get.
I try not to dissuade them from being either girly or tomboys and instead try to let them decide who they are on their own. It's not easy, with all the "Girls/boys can't do this or that" going around.
Your child is very young. Simply having these conversations with him, means you open his world and let him know it's ok to be whoever he wants. Maybe he'll grow up to be classic male, maybe not. Probably he'll end up somewhere in the middle. With you in his life, my guess is whoever he turns out to be he'll be openminded to other people and their way of life. You teach him that.