The extensively re-written and updated edition of this highly acclaimed text provides a synthesis of the latest research on the cognitive defects of dyslexia and reviews evidence concerning its biological bases.
This is a really hard book to rate-overall and as a book to dip in and out of, it is 5 star, as a book to read from cover-to-cover, as you can tell from the length of time that it took me to plough through it all, it is more like 3stars. There are times within the book that I read passages and then didn't have a clue what I'd just read. Possibly this is because I came at this as a teacher and specialist dyslexia teacher, rather than as a psychologist.
Overall, the coverage Snowling achieves in the book is phenomenal and it gives an excellent overview of all the different theories surrounding dyslexia and outcomes.
If you want a 'parent-friendly' grounding on dyslexia, I'd go for Niel Mackay or others, as a scholarly look at dyslexia and related research, you would be hard pushed to find better than Snowling.