To start the the dev environment run
mongod
then shotgun app.rb make sure you bundle install
If you want to sign in with fb, you need to add the following line in /etc/hosts (make sure you are sudo)
127.0.0.1 local.foinz.com
To run the console run racksh
To debug something add byebug and wait for the server to be intercepted.
Rspec 3 is great, it consists of three main componenets (core, expecations, and mocks). Find the links here