How long does it take for a baby to fully heal after a circumcision?

A week. Usually after a week the circumcision is healed. The skin will still look red, but the scab is usually gone at that point. Many times it will heal quicker than that.
Depends upon method. Clamp method heals within a week. Plastibell method heals a couple of days after the plastic ring falls off. Ring may take anywhere from 4 - 12 days to fall off.