Programming Erlang (2nd Ed.) Joe Armstrong
Erlang 17.5 (The book was written for that version, so that's the version I'm using.)
If you have a better or different answer click on Issues and post your answer. Anyone looking for alternative answers should click on Issues under each chapter. If you have a question about one of the solutions, post the question in an issue. While I'm working my way through the book, I'll check back regularly. After that, not so much.