I completely disagree with the previous review! I could not be happier with this book. I'm doing A2 french and first of all, I think this book is really interesting because of all the weird things the French say! =] It makes you realise how stupid and random English idioms are too.
I have no idea what the author of said review meant because under the idiom (written in french) there is the literal translation and then one (or more!) of the English (or Americain but I didn't think this was a problem at all) equivalent. For example < 'Ce n'est pas Perou' (It's not Peru) - It's nothing to write home about, it's no great fortune. >
Anyway, I also find it really useful for all of the 4 areas of learning a language as you see the little paragraph/dialogue explaining the idiom in French, then at the back is the translation in English and there are also recordings of these on the CD (which go very easily onto I-pod)...
Listening: you can listen and then read the translation to see how well you understood, or better, you can treat it like a dictation and write down what you hear (this makes you listen very carefully and tests spelling as well!)
Reading: read in French then compare understanding of translation
Writing: look at the English translation and put it back into French. This is actually quite easy because the vocab isn't too obscure.
Speaking: Record yourself on mobile or something and check your pronunciation against the recording.
So yeah, I think this is really useful and if you do the above you really remember the idiom =] My French teacher said that to get top grades you really need to include idiom so this is good for students =D