The book is not all that useful for learning the functions Studio, it even has a few errors in it.  There is some good info about composition, lighting (from a visual, mood point of view, not technical) and figure posing.  That plus the software and content make it worth the price.  But for learning don't be afraid to ask questions here or at DAZ's forums.  By the way it is a will know fact that there are more horses' arses then horses, so don't be embarrassed.