This is a basic jekyll structure. Take a look at the layout in
_layouts/layout.html and the navigation snippet in
Page urls are defined using the
permalink frontmatter, so you can call the files whatever you like. I would recommend numbering the pages to control their order in the navigation:
01-index.md 02-about.md 03-another.md ...
I'll probably add to this as I come up with cool things to do with Jekyll.