Since I feel badly about high jacking zzilla's baptism post.
Boys are circumcised on the 8th day of life. It's done in a ceremony called a bris. There are some prayers, a moyhel nips the tip, baby's hebrew name is announced, everyone drinks some wine and we eat.
Girls have a baby naming ceremony. Generally done on during a Friday evening services, though it can be done as a private function on another day. Usually done at about 3 months, there really isn't a "must do by" date like with a bris. The rabbi/cantor blesses the child, the family and gives the girl her hebrew name. Afterwards there is some sort of eating event (on a Friday night the family might host the oneg - the post-service snack time. Or if it's a private event they'll do whatever they like)