I do recommend O'Reilly's Perl Cookbook. I have the second edition, and its chapter titles include: Strings; Numbers; Dates and Times; Arrays; Hashes; Pattern Matching; File Access; Subroutines; References and Records; Database Access; Process Management; CGI Programming; and XML. It provides many examples and has a robust 30-page index, and certainly covers all the questions you've raised in this thread.