Here is a good article on the nature of believer's baptism and why we practice this ordinance as a church family. It is for "me" and for "us"; it is both personal and public. But mostly, it is for the glory of God.
My paedobaptist (baptizing of infants) friends, whom I love and for whom I would take a bullet, will find this discussion insufficient because their convictions are primarily based on the implications of their theology. But I find it to be an excellent summary of what the New Testament says.