I get this question a lot, and so here's a really nice editorial at Salon, "Let us now praise editors," written by former editor Gary Kamiya. I appreciated (and related) to his description that "Editors are craftsmen, ghosts, psychiatrists, bullies, sparring partners, experts, enablers, ignoramuses, translators, writers, goalies, friends, foremen, wimps, ditch diggers, mind readers, coaches, bomb throwers, muses and spittoons—sometimes all while working on the same piece."

If you're about to work with an editor—or have always wanted a glimpse inside your editor's head, read on.