For someone completely new to development Dockyard academy course resources [0] are open source and an excellent showcase for livebook.

For an experienced dev wanting to pick up Elixir I would suggest picking up Elixir in Action [1]. The third edition is currently in MEAP. Much more concise and great discussion of some Erlang/OTP internals too.

[0] https://github.com/DockYard-Academy/curriculum

[1] https://www.manning.com/books/elixir-in-action-third-edition

This course was just recently updated the past couple of months to go with the new major upgrade to phoenix: https://pragmaticstudio.com/courses/phoenix-liveview

Haven't actually gone through it yet, but hoping to over the next month.

If you already know Rails, I wrote an Elixir and Phoenix course aimed at you: https://phoenixonrails.com.

Use the code THANKYOU10 to get a $10 discount ;)

Educative.io seems pretty good. I just use the phoenix docs after understanding some of the core elixir features.

Phoenixonrails.com