This will serve as a guide to installing Jekyll on your local machine for the purpose of a GitHub hosted site.
Update your apps: sudo apt-get update
Install Ruby: sudo apt-get install ruby ruby-dev rubygems python-dev python-pip
Install GitHub Pages: sudo gem install github-pages
Now we can create a site, so let's name ours "mysite"
jekyll new mysite
This will set up a folder with a couple of folders and files within it.
Before we set up this folder as a Git, we are going to make some changes to the Jekyll configuration so that everything gels.
cd mysite and nano _config.yml Add baseurl: /mysite to the bottom of that file. Now Ctrl+O to save, and Ctrl+X to exit.
What we did there was create a variable "baseurl" which we can refer to in other files Jekyll uses to build our site.
Now we can add /fall2013 to the one spot in index.html file and to the four spots in _layout/default.html files so that the references aren't broken. I did this using nano index.html and nano _layouts/default.html
The change in index.html makes sure your posts are linked properly on your homepage as mysite/[whatever the name of your post is]
The changes in _layouts/default.html makes sure the CSS is linked to the proper file in your mysite directory.
So, now we have a properly set up Jekyll site that can run locally. To see if it works, make sure you are in the mysite directory and type in terminal jekyll serve --watch. Now point your browser to localhost:4000/mysite and you should see a site ready to go.
Awesome sauce. So now I would recommend creating a repository on GitHub called mysite to point the Git we will create to. DON'T CHECK CREATE A README.
Once that is complete, now get back into terminal and make sure you are in the mysite directory. Type in git init, which will create a Git for that repository, and then git add . which will add all of the files in the repository to the Git.
Now we want to commit these files, so we type in git commit -m "Added Jekyll Site.
Before we push this Git to GitHub, we want to rename our master branch gh-pages so GitHub knows we want them to host this as a site. git branch -m master gh-pages
Now we can add our GitHub location as a remote (which we will by convention name origin) by git remote add origin https://github.com/{your-username}/mysite and then push our commits to GitHub through git push origin gh-pages
Once complete, there should be a site at http://[your username].github.io/mysite/ that looks and acts exactly like your local site.
Now feel free to have fun with the CSS of the site and with creating variables in that _config.yml file to use in your posts and in the site layouts.