This is my blog, created using Jekyll Now and hosted on GitHub Pages.
Let's clear up all this "git" stuff first. Git (noun, informal) is an unpleasant or contemptible person. Git is also a distributed version control system. Try not to confuse the two.
GitHub is a place to store and manage code (and related thingymebobs) in a git repository - or repo for short. Repos can be managed from the command line, on the GitHub website, or using one of the many tools available such as GitHub for Mac. All this stuff is free.
GitHub Pages let's you build and host websites stored in a repo. You can host a website (such as this blog) in GitHub Pages. GitHub is free - I may have mentioned this - and so is GitHub Pages.
GitHub Pages uses Jekyll - a static site generator that is great for blogs. It turns your content into a static website using simple templates. Write content locally, test locally, commit to your repo, and voila - your Github Pages website is auto-magically updated. Static websites are simple; as simple as websites can be.
Jekyll Now makes light work of creating a basic blog for hosting in GitHub Pages. The code for Jekyll Now is hosted in a git repo, and it's accompanying website is hosted with GitHub Pages. I hope you're following this.
Jekyll content is written in Markdown, a simple plain text format that is easy to write and easy for programmable electronic devices to convert into HTML.
That's quite enough to be getting on with.