Every family I've known has had the best results with waiting until the child wants to learn to use the potty. And kids do, just like they want to learn to walk and talk as soon as they're ready. When your son is ready to move forward on this, he will. That could happen any time between a month from now to a year or so. But he'll get there, and if you don't make it a big, complicated deal, he'll probably get there faster.
Before then, it's fine to talk about potty training and what the body does, and to experiment with sitting on the potty, it's great to play potty games with toys, puppets, and occasionally the child, it's great to read books and watch videos, to let him watch you use the toilet, to observe how much easier time he'll have when he learns to use the potty and doesn't have to stop for diaper changes. (I thought of this as "pre-training" with my daughter.)
And at some point, he'll start showing more curiosity and indicating that he wants to try, perhaps even voluntarily sitting on the potty himself. He'll probably be thrilled by the whole idea of big-boy underpants. That's when you can let him know you'll help him remember; let him help you work out a plan so he's got some control, and go for it. Kids will often train in a matter of days at that point, with fewer accidents every day.
Children who are ready for this step toward maturity take great pride in the accomplishment. Charts and reward systems aren't even needed. Children who are pushed into it tend to become irritable and resistant, or even worse, begin to feel a sense of failure and frustration.
Here's one of several sites that gives some great "readiness" checklists. http://www.parentingscience.com/toilet-training-readiness...
Also, be aware that poop training and night training are sometimes separate steps for some children. Children can not help this.