Socials are just that, people getting together in a pub to have a drink and a chat, pub meal optional. Social meetings start about 6:30pm and happen usually once a month, usually on a Thursday.
London Perl Mongers has two low-traffic mailing lists which are hosted by nice people at Renater on open source Perl mailing list server software called Sympa. There is a general discussion list and an announcements list. The general list is subscribed to the announcements list so you don't need to be on both.
You need to use the email interface to subscribe because the web interface is
too much like hard work.
Subscribe to london.pm
The archives are here:
https://groups.perlists.pm/sympa/arc/london.pm
There are also historical archives of the list, from before
June 2001 at
http://www.mail-archive.com/london-pm%40lists.dircon.co.uk/
irc.perl.org:6667 #london.pm - you'll need an irc client, a piece of string and one of those washing up liquid bottles.