how do I get my 3 year old excited and ready for a baby brother or sister?

just talk to your kid and tell them it's a little baby and he has to help mommy and teach it, and love it.

I told my three year old son he has a brother or sister in my stomach and every night when he tells me goodnight he says goodnight to my belly and now we know its a girl so he is always asking about mommies baby girl sister<