What 'ChatOps' books and resources are available?
One of the people active in ChatOps community is Jason Hand from VictorOps, who wrote a book published by O'Reilly called Managing Operations in Group Chat. This book is available for free as part of their content marketing campaign. The previous ChatOps for Dummies is no longer available and is replaced by the above book.

You should definitely take a look at Slack Apps, especially the Developer Tools. There is article by SlackStorm on how to integrate Ansible and Slack.

You might also monitor the subreddit on chatops. There is a long sidebar of resources including the video from GitHub ChatOps presentation and many more.

I would also recommend to look at Cog from operable.io and the Cog Book.