Soft Real Time App with Erlang

I recently started learning Erlang and at this开发者_如何学JAVA point I'm comfortable with most concepts and syntax. I'd like to continue my learning by using Erlang to build a "simple" instant message application. I'd appreciate suggestions on which resources (books, websites, etc.) can help me along.

Learn You Some Erlang has a bunch of chapters on concurrency, networking, and OTP. You might also be interested in reading the ejabberd code, though it might be a bit involved.