The book is not very well written: too much simplification when it should have not been simplified and explanations are done in a too roundabout way.

And avoid writing math formulae but instead describing the formulae in English doesn't make the math concept more understandable. (Instead of writing Σ|xi-yi|, "the sum of the absolute value of the difference between the elements of the vectors")

Good for skimming through, but since I am incapable of skimming I guess I will just go back to watching Andrew Ng.