Bee-Watchers & Bee-Watcher-Watchers

The Onion inventories 6 Memorable Books About Writers Writing.  Why 6 books?  Because that's how much space they had to fill.

Off the top of my head, I'd throw Nabokov's The Real Life of Sebastian Knight and Stephen Dixon's Old Friends in there.  (I haven't read The Tunnel, but it qualifies.) There must be hundreds...any other favorites worth a mention?

(UPDATE: Apparently, I'm not the only one who noticed...Condalmo suggests Wolff's Old School.)