The thing I find with books from the library and bookstores etc is a lot of them aren't written in New Zealand and a lot of the fish species in them you cannot even get here! The water is different here, the temperatures are different, Which can be confusing for newbies.
I agree also that most books contradict themselves with others.
Just like the forums. But you cannot 'probe' the book for more information or ask the book to detail something a little more if you don't understand.
What works for one person - many not work with someone else.
I'm particularly fond of native fish (which apart from a few members on here) there are absolutely NO resources out there for keeping them.
Personally I think its great to have a wide range of opinions!!