If you already have a full Ruby development environment with all headers and RubyGems installed (see Jekyll’s requirements), you can create a new Jekyll site by doing the following:
# Install Jekyll and Bundler gems through RubyGems
gem install jekyll bundler
# Create a new Jekyll site at ./myblog
jekyll new myblog
# Change into your new directory
cd myblog
# Build the site on the preview server
bundle exec jekyll serve
# Now browse to http://localhost:4000