The wryly written books actually provide some usable facts: the Bluffer’s Guide to baseball, for example, gives concise bios of the game’s most famous players. As “The Bluffer’s Guide to Bluffing,” the series’ introductory volume, says: “A little learning is a marvelous thing, and since that is all we are ever going to have anyway, we might as well get to know how to spread it thinly, but effectively, like the last smidgen of peanut butter on the heel of the loaf.” The publishers, it seems, have learned the art of bluffing well. They readily admit that the guides are a licensed version of a series published in Britain.