If you look through this book when you start playing Tabula Rasa, it would appear to contain maps of every area. This is because you've just started playing the game and don't know what to look for. At lower levels this book is very useful, containing maps of the instances and locations of Logos within them. It even gives you a heads-up on some of the tactics you'll need to employ against many enemies.
After playing the game a few days and getting past these new areas, you'll start to notice some things missing at first. First it will be a few quests missing from the book, then a few of the smaller instances. Later on it will become inexcusable. Large important instances will be missing from the book, without even so much as a map to look at.
I gave this book 2 stars because it does contain a lot of information, and for lower level players it does have useful maps. Later on you'll have to rely on fansites (from about 23-50).