B.T.
He is absolutely NOT ready if his little nerve endings aren't fully developed and functioning, (which occurs at about age 2), and he begins to show signs of recognizing when he has the urge. You watch for this, and you talk about it. You invite him to the bathroom when YOU go, also have your husband do this, so he has the sense that this is "what we humans do", we go here, we sit here, we do this, etc. In other words, you "talk" him through it, simply. If you're so modest that you can't do this in front of your child, this won't work...or you'll have to overcome it.
When the child gets a visual grasp of what adults do, he'll become more receptive. Then you bring a tiny potty home, and explain that this is for him "when you're ready to try it." Then you keep taking him with you. You invite him to try his, "in case you feel like going too", but you never insist. You keep this up, it becomes a natural process to him, and at some point, he will try it. You don't scold when he misses, you don't necessarily praise when he gets it right. at least, not a big loud celebration. That makes it too big a deal, and you never want it to become a point of contention or conflict...point being, don't make a huge deal about any of it. Nothing fearful, nothing shocking, no pressure, no trauma. I trained 4 children that way, and we never had a single issue. By about 2 1/2, they were done, and it was never a difficult process. B.