First of all: All of the O'Reilly books are excellent. I have the Perl Cookbook and the Pocket Reference, and make extensive use of both. I actually started with _Learn Perl in 21 Days_. After about 10 days or so, I knew enough to not need the book any more. :) After that, the Cookbook is very useful. Something else to point out is the documentation that comes with Perl. There are many, many manpages that come with Perl (type 'man perl' to get started). Additionally, you can use 'perldoc' ('perldoc perldoc' to get started there) as well for more documentation, especially about the various modules that Perl has.