This book is an excellent introduction to learning arabic. It is very well structured, building up steadily through the arabic alphabet and also steadily a basic level of arabic vocabulary: of the order of 300 or 400 by the end of the book.
The mp3's work really too, there are plenty of examples of different constant/vowel combinations and having them in mp3 format gives me the time to familiarise myself with these new sounds as I travel to work or do some housework. The other great thing is the quality of the audio, each sound is very clearly pronounced.
Lastly the book is very attractively laid out with beautiful colours, pictures, graphics plus each chapter has exercises to complete (answers at the back of the book).
I've been learning arabic for just under 3 months now and I am amazed with the progress I have already made!