Coin books come in several types. Among them are books that discuss one or a few specific types of coins and those that offer information on coins of a country or a region, or of a time period.
If one is seeking information on pricing, there is currently a huge problem. Coins containing precious metal can change value in a day, so no coin book can remain current. For coins containing only base metals the prices offer a good snap shot of the values at the time the book was compiled. But, there is also a lag time from when the prices were real accurate and when the book can be purchased. Usually, slowly changing prices are close enough for most purposes.