C.M.
3 year olds are testing their limits. The not listening is totally normal. Be kind but firm and consistent. Personally, I don't care for sending kids to their rooms. I think their rooms should be a safe place, not a place for punishment or attitude readjustment. If sent there too often for punishment, he might not want to go to bed or even go play in his room. I would suggest a "naughty chair" or "naughty mat" placed away from everyhing so he has to sit w/ no talking or books and be bored. Talk to him and tell him what will happen if he doesn't listen to you and then follow through. No disussion, just pick him up and put him on the chair/mat. If he gets up...and he will...still no talking, just put him back. He will get it eventually and you will not have to yell at him or use any spanking. It works!