This repository uses Jekyll with Github Pages to create a personal website using the "minima" gem. This gives a simplified setup for a blog style website. To make a website like this, I recommend you start at the Jekyll website doc page to learn about Jekyll, and GitHub's Working with GitHub Pages to get the idea of what GitHub pages can do for you. Then GitHub's Setting up a GitHub Pages site with Jekyll.
I found that it really helps to understand Jekyll and a bit about "bundler" that is described there. Get a test site working using the quickstart, and do the tutorial too. Then try the GitHub pages instructions- it seems that sometimes a step or two related to bundler is omitted, as least as far as setting up on a Mac went for me. But understanding bundler a bit lets you fix those issues and get a site running. You can also use a site like mine (or anyone else who uses Jekyll on GitHub Pages) as a guide of what Gemfile and other stuff you need.
Left myself some notes about my particular setup and how to update the site on the wiki