I have not looked at this particular book, so this is a generic observation.
Many of these types of books (i.e., books for a more-or-less lay audience) have serious shortcomings. They are often written by people that themselves don't have a firm grasp on the subject and who think that they can help others by basically expounding upon their understanding of it, which is full of holes and misconceptions. When that is the case, the book can actually represent negative knowledge in that you end up knowing less than you did before, because you are now either more confused or, worse, you think you "know" things that aren't actually true.
Even books that don't have this problem -- i.e., written by people that really do know the material -- frequently suffer from the author's lack of ability to write well combined with little-to-no editorial review stemming from many of these types of books being self-published or close to it.
But this is NOT to say that ALL of these books are bad, but you should make the effort to review the book before you buy it, if possible, or buy it with the awareness that it's a gamble and don't pay more for it than you are willing to throw down the drain. That way, you aren't too disappointed when it turns out to be junk and are greatly surprised on the occasions that you find a useful gem.
Many of these types of books (i.e., books for a more-or-less lay audience) have serious shortcomings. They are often written by people that themselves don't have a firm grasp on the subject and who think that they can help others by basically expounding upon their understanding of it, which is full of holes and misconceptions. When that is the case, the book can actually represent negative knowledge in that you end up knowing less than you did before, because you are now either more confused or, worse, you think you "know" things that aren't actually true.
Even books that don't have this problem -- i.e., written by people that really do know the material -- frequently suffer from the author's lack of ability to write well combined with little-to-no editorial review stemming from many of these types of books being self-published or close to it.
But this is NOT to say that ALL of these books are bad, but you should make the effort to review the book before you buy it, if possible, or buy it with the awareness that it's a gamble and don't pay more for it than you are willing to throw down the drain. That way, you aren't too disappointed when it turns out to be junk and are greatly surprised on the occasions that you find a useful gem.