That image is the editing copy of Alex Van Helsing: Voice of the Undead, or as I call it AVH2. We're in a period now where the edits are being done as though this were 1978; I'm making edits on the same paper the editors at HarperTeen make edits on. This makes me a little self-conscious; I notice the copy editors at Harper never seem to get coffee stains all over the paper when they send it to me.
Those tabs? You can't tell, but those are how I keep track of global changes. They're coded with letters-- A for information about Alex, M for Ministers, a plot point I need to add a few lines about, S for Sid, R for Reactions, another plot point. And so on. It's useful to have them tabbed like this so I can do all the edits regarding a particular issue at once. If the edits get longer than a few lines, I type them up on a computer, print them out and staple them to the paragraph being replaced.
There's some evidence that the best work is done through mixing word processing and handwriting-- I read recently that it's more efficient to draft on a computer but edit on paper, and for me this is true.
Halfway through the tabbed edits tonight-- the rest should be done tomorrow night.