Reading a book is not the critical step. Applying the book's sensible concepts is. Most players who win at poker do not do so because they read poker books. A book might in fact be responsible for an epiphany in many players, but even that is not what makes them a winning player. What makes winning players is study, dedication, motivation and the self-control to consistently follow the path lit by those three.
Study includes reading.
That's one aspect. Good players should study poker constantly. I have read thousands and thousands of words on poker. Coincidentally most have not been in books. David then very bizarrely labels me as non-reader or whatever.