Local Twins blogger Seth Stroh has released a book covering 175 players in the Twins minor league system. Here is a link to his description of the book, including ordering information.
This is really the first time anyone has done this kind of in-depth reporting on the Twins system. Of course most of these guys will never where a major league uniform, but that is half the fun of following the minor leagues. You can pick out favorites and follow their struggles and successes. This kind of book is now available because independent journalists, like Seth, have developed audience on the internet.