To keep up to date with Quake and Quakeworld in 2015:
Twitter: general Quake / QuakeWorld news, events, links... qw_tips
Facebook: Several facebook groups, just search. the "official" QuakeWorld page: face
Steam groups: add your steam Quake lovers! qwfriends and QWCTF
Reddit: Arena first person shooters in general, Quake is there too Arenafps and /r/Quake and /r/QuakeWorld

and ofc

http://quakeworld.nu/
quakeone

and so many many others... about mapping, modding, modelling...
IRC is where we meet WebIRC

Servers all over the world, hundreds List of active servers Just look at the image!

Quake TV (QTV)

Interested? Get nQuake and you'll be playing in 5 minutes
nQuake

Yes this is 2015, next year is Quake's 20th anniversary