Learn Punctuation

Learn punctuation; it is your little drum set, one of the few tools you have to signal the reader where the beats and emphases go. (If you get it wrong, any least thing, the editor will throw your manuscript out.) Punctuation is not like musical notation; it doesn't indicate the length of pauses, but instead signifies logical relations. There are all sorts of people out there who know these things very well. You have to be among them even to begin.
ANNIE DILLARD