Learn Rails 4 native testing: http://guides.rubyonrails.org/testing.html
Watched a great video tutorial from Rails for Zombies.
Read a great post on how to use MiniTest. I think it is the default testing library in Ruby now. http://www.rubyinside.com/a-minitestspec-tutorial-elegant-spec-style-testing-that-comes-with-ruby-5354.html
The article above references a talk about Minitest by its author. http://www.everytalk.tv/talks/159-Cascadia-Ruby-Size-Doesn-t-Matter
Made a schoolboy error when trying to understand a bang in front of a statement instead of after. Posted a Stack Overflow question then slapped my forehead when I got the answer.
15 TDD steps to a rails app