O'Reilly's Learning GNU Emacs, Third Edition is probably your best bet, it taught me an awful lot about emacs, and I'd been using emacs for years before I read it.

Emacs has an excellent help system (C-h ?) that can teach you a lot about Emacs. Apropos (C-h a) is very useful for searching for the keystrokes to do something. If you've got a few weeks to spare, C-h b will show you all ~700 keyboard commands:) The Emacs Manual is also available in the help system (C-h i s emacs RET)

The emacs wiki is a very good resource, Learning About Emacs may help you.

Finally, for use with Perl, cperl-mode is a must, but get a more recent version than the one that ships with Emacs