Pages
Prosthetic Foreheads said:
Okay, so now everyone knows to send five pages with the query. My question: Does it have to be the very first five pages? Maybe it's a stupid question. I've seen it phrased as 'the first few pages' and 'a five page excerpt.' Is it just understood that the excerpt is the opening passage?
I'm not sure what someone means by "excerpt," but the first five pages of your novel are far and away the most critical. These are the ones that will either hook and agent/editor, or make them say "No, thanks." I doubt five pages from any other part of the novel would do any good because they wouldn't be in context.
The opening of the novel pretty much lets an agent know a ton of things about your and your writing than no other pages from the novel can do.
Write five opening pages that are good enough, and the agent will want to see the rest of the manuscript. I'd say always send the first five pages, no exceptions. If you don't, the agent won't be able to tell how well you can hook a reader, and will, at best, wonder why you didn't send the first five.