"Addison Wesley" publishes traditionally good books which contain mainly information to the point the question.
In the "Perl Medic" you won't find a lyric intro about what is Perl, its syntax, data structure etc. Instead of it, Petter J. Scott has given consideration to principles and approaches to develop clear understanding, easy distensible, scalable and stable Perl applications.
Chapter by chapter, the author explains discipline of Perl coding, methodology of testing, diagnostic, logging perl applications.
In my opinion, "Perl Medic" is very-very helpful, intimate book which will help Perl developers to get skills of good coding!
Hope that my short review will help you to buy and read that excellent book.
In reply to Perl Medic: Transforming Legacy Code by Peter J. Scott by nite_man