Sessalee Hensley is in charge of buying fiction for Barnes & Noble. “How many copies will be bought – of Proust, McMillan, John Grisham, Jonathan Franzen and Ms. Hensley’s favorite, Barbara Kingsolver – how they’ll be apportioned among the 652 Barnes & Noble branches and 200 B. Dalton Booksellers in her fiefdom, how they’ll be placed and positioned–this is all part of the gig. ‘There are some books that I’ve gone through three, four, five revisions of how I’m thinking about them,’ says Ms. Hensley, 48. Concern that she’s decided wrong sometimes keeps her up at night. Concern that she’s decided wrong keeps publishers up as well…”