General Resources

[Will]

Official class websites:
http://www.ai-class.com/
http://www.ml-class.com/
http://www.db-class.com/

Subreddits for each class:
http://www.reddit.com/r/aiclass
http://www.reddit.com/r/mlclass
http://www.reddit.com/r/dbclass


IRC channels (Chat rooms):

Web interface:
http://webchat.freenode.net?channels=aiclass
http://webchat.freenode.net?channels=mlclass
http://webchat.freenode.net?channels=dbclass

Or if you have your own preferred irc client:
(All on irc.Freenode.net)
#aiclass
#mlclass
#dbclass