It is funny, definitely the same kind of humour as on the show itself, and often very much at the expense of the three presenters, plus the Stig of course. It's not to be confused with the kid's range of TG books that are also out there, nor with the TG 2009 Annual, which is also for kids.
Won't take you long to read though, and it may only have limited re-read value to you; I can imagine a lot of them ending up in charity shops one day!