Free Ruby Books and Courses
Written by two professional Ruby developers, this book "gives you hundreds of solutions to real-world problems, with clear explanations and thousands of lines of code you can use in your own projects."
Head First Ruby
The Head First series takes a more visual approach to teaching programming than most series. The book "uses a visually rich format to engage your mind, rather than a text-heavy approach to put you to sleep."
The Ruby Programming Language
This book is considered to be the definitive Ruby resource.
Code Academy: Learn Ruby
"In this course, you will gain familiarity with Ruby and basic programming concepts—including variables, loops, control flow, and most importantly, object-oriented programming. You’ll get a chance to test your understanding in a final project, which you’ll build locally."
This course gets you started with Ruby in as little as 30 minutes with interactive online editors.