This book has many virtues. It is very clear an assumes no prior knowledge, for one. Also, Lowe makes his text useful to both Windows and *nix idioms. For most every function and piece of syntax that Lowe introduces, he provides a useful exercise for the reader, to help solidify his/her understanding (thus the 'workbook' in the title). The 'answers' that he provides come with good explanations and are quite clear.
Since I bought this book used, it was not "Web Charged." In fact the page does not exist at all. I did not find this to be very disadvantageous, though, as the exercises in the text were adequate.
Keep in mind that this is not a reference book. As I was working through it, which at 600 pages or so took a few months, I would often need to go back and review something that I had learned. And while Lowe's explanations are very clear , they are not exhaustive, and "The Camel" (Perl Programming, 3rd ed, by Larry Wall et al) makes an excellent reference companion to anyone serious about learning perl.
If you want to dish out the extra cash, and need whimsical stories about Gilligan and Mary-Anne, then you should probably get the OReilly "Learning Perl" book instead of this one. But Lowe's Interactive Workbook is no joke, and if you do the exercises and invest in it it won't let you down. And you can't beat the price.