Let's Get Going with Org-Mode
I was a bit shocked to see the author using the gui :) If you're already into Emacs the David O'Toole is better imho 
<a href="https://orgmode.org/worg/org-tutorials/orgtutorial_dto.html" rel="nofollow">https://orgmode.org/worg/org-tutorials/orgtutorial_dto.html</a>