This is pretty typical behavior for little ones. My kids do the same thing all the time. You just have to be firm and consistent. Do not give in, ever. If you do your son will walk all over you. Also, don't use physical punishment. I was spanked and it only made me afraid of my mom. Anytime I have spanked my son's hands it encourages him to hit more. It just doesn't work. He's still young enough that taking away toys or privileges may not work, especially if has plenty of other toys or activities. Time outs have worked with my kids but most of the time just knowing that we're upset (either because of a mad face or a firm voice) is enough. My kids absolutely hate getting in trouble.Can you give some specific examples of the things that he does? You will probably need to use different techniques in different situations. With two naughty toddlers I know all about who to discipline and would love to give you some suggestions for specific situations.