To be fair, the Beginning Perl wasn't published until June of 2000; however, Perlmonks was still in its infancy at this time; for proof, take a look at Ovid's homenode number, as he joined the monastery in early June of 2000.
I cannot say if the book is 100% correct or not since i'm just a beginner.
All i can say is that I went into Barnes and Nobles as a complete perl (and programming) noob and i took the llama and this book and i compared them. I noticed the llama was complicated and indeed confusing me. So I bought this one, and i haven't felt sorry yet. I think it is a very good choice to start perl with if you are a complete noob in programming.