Write your drafts under the _drafts folder with a filename like 2000-01-31-lol-wut.md
When you're ready to publish a post move it into the _posts folder.
git push
Setup with just the gh-pages branch so anything you do in this branch will be displayed on the site on push. (It can take up to 10 minutes to be reflected)
jekyll serve --watch --baseurl ""
Run the following line from within the project and make your changes. Jekyll will automatically update as you updated the blog