Haven't gotten around to read many Oracle books, but it seems to be decent -- if compared to those (awful) other ones! But then again, what's the WWW for? It's getting on my nerves (being glued to the screen for reading all thee time), but buying those thick, heavy programming books are very, very expensive, so ...
Anyway: It's okay as a reference book, not though, if you haven't a clue about PL/SQL and want to start learning PL/SQL programming. Consider this a warning and friendly piece of advice.