Ensembl Coding Standards: http://web.archive.org/web/20010306093650/www.ensembl.org/Docs/wiki/html/EnsemblDocs/CodingStandards.html
Slash Style Guide: http://slashcode.com/docs/slashstyle.html
P5EE Blue Style Guide: http://www.officevision.com/pub/p5ee/software/htdocs/P5EEx/Blue/perlstyle.html
Perlmonks Discussion on Style Guides: http://www.perlmonks.org/index.pl?node_id=209555
Perlmonks Discussion on POD: http://perlmonks.org/index.pl?node_id=94969