Barnes & Noble said today its nook e-reader is now in stock online and will be rolling out in the majority of its stores by mid-week. Barnes & Noble sold out of nook stock online over the holidays due to high demand, which exceeded the bookseller's expectations. Since then the company has ramped up production and is shipping stock to most of its stores this week. Customers can visit the Barnes & Noble nook In-Store Locator to find local stores with the device in-stock.