Maybe you are a recent convert, or perhaps you've attended Mass your whole life, but there are still things that puzzle you, like: when you should genuflect and when you should bow; what the different books used at Mass are and what they contain; the meaning of words like "Amen," "Alleluia," or "Hosanna"; what to do during the sign of peace. You aren't alone. The How-to Book of the Mass not only provides the who, what, where,...