ARS Technica had a short chat with coauthor Kyle Orland, you can check it out over here.
"Sure, Farmville isn't a particularly difficult game—it practically holds your hand in telling you how to play, and there's a limited amount of strategy to playing," Orland told Ars. But he argues that many people who play the game don't have much experience with video games, and may require some extra help. "Some of the sections of the game—especially the farmer's market and some aspects of animal tending—require multiple, time-lapsed steps to complete successfully, and the game only gives one screen of text-heavy explanation for how to go about them." The book breaks down these tasks, and offers full-color images to help gamers follow the instructions.You can buy FarmVille for Dummies at Amazon for $12.61.