How did you guys learn perl so well?

By writing code and testing it, reading code, reading books and reading and writing on perlmonks.

any recommended books/websites?

Lots, depending on your level of knowledge. "Learning Perl" and "Modern Perl" are good for starters, many good books address higher skill levels.

http://perldoc.perl.org/ and http://search.cpan.org/ are among the most valuable Perl websites for me.