How about that? Usually you watch a movie and go, "nyah.. the book was better." And, oddly, Psycho is that rare breed where both the first movie and the second are better than the books. Of course, the original Psycho is a good story, and the movie is a flawless masterpiece. But this is something different altogether - now we can say "yeah, the movie's pretty excellent actually. But the book? Gah - what the Hell was Bloch thinking?!"
Trust me, this is one time you'll be glad Bloch didn't get a say in the making of the movie (the story is 100% different). Whereas the movie has Norman going back to the motel and taking up where he left off, in this there's an (admittedly ahead of its time) idea of the original story of Psycho being made into a movie, (eat yer heart out Scream 2). But instead of making Norman, like, a PART of the story, they turn the whole book into some stupid who-dunnit filled with boring characters and really stupid plot devices. And the ending will have you throwing the book straight out the window.
I really wanted to like this, because I've enjoyed the entire Psycho movie series (even the fairly naff fourth part). But Bloch succeeds in taking Norman Bates and completely ruining him. Thankfully this book has been largely ignored, because it really doesn't deserve to be part of the Bates' legacy.
Stick with the movies.