Well, I wasn't sure if it was a good idea when I decided to buy that book. I was afraid it would spoil the experience of the game but, I bought it anyway and, to me, it was a great decision. The most interesting part to me wasn't the sections about all the quests but, mostly, the first sections of the book where there was lots of interesting informations on the character creation and the abilities you can have in the game. It helped me to shape a better character more suited to the kind of gameplay I wanted. Also, there are lots of tables containing infos on where you can get training for your ability of choice, what interesting objects you can hope to find, etc. The map is also nice to have because, there are lots and lots of place to go... I played 120 hrs before finishing the main quest and yet, I think I did maybe one third of what the game has to offer. I might go back to it later to finish some other guild's quests. Buy the book if you want to invest yourself fully into the game, it's a great help!