What we did to start, was just to start talking about it more. Saying that when DD was a big girl, she'd use a potty like Mama and Daddy and wouldn't use diapers anymore. Do you have a little potty chair? If not, I'd get one and put in the in bathroom, just to give him some time to get used to it.
When we were ready to start PT my DD, we put her in panties and told her that she was a big girl and no longer wears diapers. We told her to tell us when she had to go potty. Of course at first, she didn't tell us. But every time we saw her starting to go, we rushed her to the bathroom to sit on the potty. Any time she got anything in the potty, she got a sticker and we made a BIG deal about it. As time went on, she started being able to control her body more and she'd sometimes stay dry until we could get her to the bathroom. It continues to improve as time goes on. We do put a pullup on her for nap and bedtime but there have been times where she insisted on wearing panties to bed and we never force her to wear a pullup in those cases.
More than anything, I would say stay positive. Potty training is HARD work for you and for them. It can be so frustrating when they keep having accidents but accidents are how they learn. I'd say we had close to 20 pairs of panties when we started and there were days when I had to do laundry so she'd have enough to get through the day.
Jodi (27) DH (24) Shaelynn (2)