Learning Perl is an excellent book. It's one of the reasons I still consider Perl a pretty good teaching and learning language, despite it's bad reputation among some programmers. All of the big O'Reilly books for Perl are truly excellent, in fact, and a big part of why O'Reilly developed such a reputation for excellence (which, I think, has faded somewhat in the past decade or so...at least for me...I don't tend to automatically choose the O'Reilly title, anymore, whereas that used to be what I always picked up first).