Rowder,
1. As soon as you receive you Divorce Certificate you might want to take a copy of it and get it notarized and forward it to CIC. With a covering letter stating your case and your spouse will be stuck off your application.
2. After consultation with your child's mother you will have to decide who your child is going to be staying with after you go to Canada. If its going to be your wife (former) then you will have to intimate CIC in the same letter. The child will have to undergo a medical test when the time comes alongwith you. If the child is going to be with you them intimate them likewise.
Mike