Google plans to initially offer about a half-million books, Where readers will be able to purchase the books directly from Google or from online bookstores such as Amazon and Barnes & Noble. Google plans to share the sales with both publishers and the online bookstores. For books sold directly from its Web site, the search giant said at the book fair that it would give publishers 63 percent of the sales and keep 37 percent itself. For books sold through Amazon or other retailers, the publisher would get 45 percent, while the retailer would get almost 55 percent with a…