I do the yoga instructed by this book with my daughter and we both really enjoy it on the whole. I would definitely recommend it as I think my daughters skills (7 months) have come on leaps and bounds.
My only critcisms would be that you need to keep flicking back in the book if you don't remember how to do the poses that are incorporated in the routines, so making notes for yoursef is best. I would also say that the book is a little 'preachy' at times, damning the use of bouncers, walkers and basically saying you're cruel for using them! However I just tend to ignore those bits!!