The book is definetely written for those who at least have some (or maybe a little more than just "some") programming background, and willing to learn Perl from the author of the language.
I read the first edition of the book, which was about 200 pages, or something in that range, which filled my mind with nothing but questions. Current edition, however, could answer to all of those questions (well, almost). Of course, to make it answer them I had to re-read the book four times. But none of the books I currently own (and I own quite a few) could've taken me to the innards of the language so deep no matter how many times I had read them. So the book is of value.
The Camel book, especially, does a great job on Regular Expressions and pattern matching. If you want to learn RegEx of perl in very details, you definitely need listen to the author of Perl. "Mastering Regular Expressions" by Jeffrey Friedl is also a good choise, but doesn't include the latest updates.
Formats aren't covered very well though. So you might consider "The Lama book" for that ("Learning Perl"). Still, none of the books can tell you about the innards of the Perl in so much detail overall than "Programming Perl".
OOP is also toched upon in the book. Since purpose of the author is not to preach you OO lingo (but plain Perl), you'll treat that part just as an intorduction to OOP and consider "Object Oriented perl" by Damian Convey as the next text book.
I found chpater 14, "Tied variables" very helpfull though. It might remind you of DBM/Berkley DB, through the syntax
tie my %db, 'AnyDBM_File', 'my_file', O_CREAT|O_RDWR, 0664;
but unfortunately it's not about DBM at all. It is about how the "tie" function works, and teaches you how to create your own classes for implementing with "tie". After that chapter, I even had to update some of my classes and saved lots of time for their updates.
"Compiling", chapter 18 ,is a must read chapter for those who "live & breath" with Perl (like me, may be ?).
I don't want you to buy the book unless you have a good understanding of Programming or/and have knowledge of some programming languages. Otherwise, it won't help at all.
If your purpose is just to get started with Web applications, go for "CGI progamming 101" by Jacqueline Hamilton. It is a good start. But if you want to go even deeper, "Learning Perl" and "Perl Coookbook" is the next choise. Keep the "The Camel" book as the next (but definitely, not the last).