I’m running Xubuntu 16.04. This method should be the same/similar in any Debian/Ubuntu distro. These are the steps I followed to get this thing working, using the terminal:

sudo apt install ruby ruby-dev ri bundler build-essential git
sudo gem install jekyll
sudo gem install minima

Note that if the Jekyll version is newer than the supported version on GitHub (see the GitHub dependency versions page) then you will need to install the latest supported version of jekyll instead, like this:

sudo gem install jekyll -v 3.1.6

Next, you need to create a special repo in GitHub for your site. In GitHub, create a new repo, and name it:

whatever-your-username-is.github.io

Finally, grab a local copy of the new repo:

git clone https://github.com/whatever-your-username-is/whatever-your-username-is.github.io

Create a brand new Jekyll site with the same name:

jekyll new whatever-your-username-is.github.io

Move to the directory:

cd whatever-your-username-is.github.io

Test your site locally by running this command, then go to the site it shows you in the terminal (default http://127.0.0.1:4000):

jekyll serve

Once you know it’s working, or after you make whatever changes you want, throw it back up on GitHub!

git push

After you successfully push your newly created Jekyll site to GitHub, wait maybe 2-3 seconds (not really, it’s just amazingly fast) and then go to:

http://whatever-your-username-is.github.io

Start blogging!