Perl bookmarkers

Perl & LWP :
http://lwp.interglacial.com/index.html

Perl PAR :
http://par.perl.org/wiki/Main_Page

Perl In a NUTShell :
http://docstore.mik.ua/orelly/perl/perlnut/index.htm

Perl cookbook :
http://docstore.mik.ua/orelly/perl/cookbook/index.htm

Advanced Perl Programming :
http://docstore.mik.ua/orelly/perl/advprog/index.htm

Practical mod_perl:
http://modperlbook.org/

Mason:
http://www.masonbook.com/book/

log4perl:
CPAN log4perl
Retire your debugger, log smartly with Log::Log4perl

file lock:
File Locking on perlmonks