This may be one instance where instead of looking for a book you may want to look at collecting a set of articles/reviews/protocols that can be used instead. This field is changing constantly and things are always in a flux.

There is Biostar Handbook. It does not cover "all aspects" of NGS but is a good start. It is not free but you could talk with @Istvan on a solution.

Any more advices !!! me too, new to this world & need to know how to start?