First of all, no it aint a cheat book. Its a hints and direction book.
I love this book, it has detailed info behind all the missions and side missions and goes into quite alot of detail. For instence, it tells you the route that you need to take, usefull weapons etc in the area, tips on how to complete the mission and things to avoid as so not to fail the mission.
It even tells you about a person that, if you go up to them, they give you $100.
It also has a large pullout map that highlights all the weapons in the game and where all the random people are that give you sude missions.

Is this a cheat book because i think i need it i have the game i have hade it for a week and i have 30%completion is this the cheat book ?

This is the first strategy guide that I have ever bought for a game and certainly not the last. It has very detailed maps of weapon, health, body armour, stunt jumps and flying rats. The guide is very well set out and gives perfect explanations of how to complete the missions.

Its a definate buy and Play.com beats all highstreet store with its fantastic price.