Rob, the get a head book is legit. I got a copy when I went through and it really helped. There's a lot of first-hand experiences on PPrune but it's good to have a copy for reference. CTC interview is very much asking you about yourself, examples of when you overcame obstacles, low points, what got you interested etc. so it doesn't have the answers, but gives you good idea of the questions to expect..
I got an e-mail confirming the dispatch of it almost immediately. I was a little concerned considering it was only advertised on a naff website but it arrived pretty quick. I traced the order through paypal anyway.
Good luck
Ant