This guide will walk you through the steps for setting up a full functioning Ruby environment setup on your local machine. The process varies depending on your operating system. If you have access to an Apple computer running a recent version of OS X or a desktop Linux version, I'd highly recommend using it. Although the tools for Windows have greatly improved over the last few years, development is still smoothest on a *-nix based operating system.
OS X comes preinstalled with (typically outdated) version of Ruby. For various reasons, it's better to install a Ruby version manager to allow you to install multiple versions on your machine and easily switch between them. There are a number of different open source options available, but we will use rbenv.
The easiest way to install rbenv is through Homebrew, a nifty little package manager for OS X.
To install, open up Terminal (in your Applications > Utilities directory) and run the following command:
ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
If you already have Homebrew installed on your machine, you may need to update it first:
brew update
Run the following command to install the latest version of git:
brew install git
Once Homebrew is installed, run the following:
brew install rbenv ruby-build
This will install rbenv and ruby-build, a little utility that will download and compile ruby versions for you. After
installation, you'll need to add a line to your bash profile using nano (or your favorite text editor):
nano ~/.bash_profile
Paste the following at the end of the file:
eval "$(rbenv init -)"
Then, Save and Exit (Control-X, Y to save). Close and re-open a new terminal window to apply the changes.
We'll use one of the latest versions of Ruby in the 2.x branch:
rbenv install 2.2.0
This may take a while. Plug your laptop into a wall outlet and go brew a cup of coffee.
When complete, run the following to set this as your global Ruby version:
rbenv global 2.2.0
Run ruby -v and you should see something to the effect of ruby 2.2.0.
And that's it!
Download RailsInstaller for Windows and check out the installation help video.