Verdict: diamonds wrapped in stinking hazardous garbage. Value that how you will.
I learned that in some prisons you're not allowed blu-tack, that cell thefts often happen during fights when everyone is distracted, and that most prisoners serve only half their sentence inside. The advice for what to take in with you and what to do when you arrive is surely very helpful.
However, I am not convinced by this author. He opens essentially by saying: "prison isn't the violent place you think it is - it's not that bad". False representations in the pansy media would make you think prison is, quite frankly, hellish.
He proceeds to treat fist fights as if they're as normal as handshakes, and mentions in passing the official squad of slave-wage prisoners dedicated to cleaning up pools of blood, sick and faeces in the aftermath of violent incidents. Cattermole is unwilling to acknowledge that this does constitute a high level of violence, and unwilling to see why it may not have happened to him.
It smacks of someone trying to seem tough and cool, to the detriment of all else. To the point of refusing to acknowledge that being under lock for 23 hours a day is inhumane. Cattermole publishing a book saying that he didn't really care and preferred being in his cell - no matter how true for him - is extremely callous. The isolation and stress of being locked up in cell are major contributing factors to the devastatingly high rates of self harm and suicide in prisons.
He talks about getting this book secretly printed by his Moorgate banker mate, and doesn't seem to register that prison may have been a slightly easier experience for him because of the class, race, gender and mental health privilege that allows him to advocate for himself, and places him under less stringent surveillance.
In brief: the anecdotal evidence of a person who is able to publish a book is far from representative of the average experience of incarceration. A good author will acknowledge this. Cattermole does not.
While his practical advice is surely very helpful for those who can access it, the central thesis of the book that surrounds it is that prison is survivable if you do all the right things. This is just not true for a great many people, and it's grossly misleading to the book's majority middle-class readership.
Angela Davis and Mim Skinner are far better alternatives for anyone wanting to learn about prison.