username/username.github.io naming scheme.
username.github.io or 
orgname.github.io first. 
username.github.io, 
where username is your username (or organization name) on GitHub.
git clone https://github.com/username/username.github.io $git checkout master
~$cd username.github.io ~$echo "Hello World" > index.html
~$git add --all ~$git commit -m "Initial commit" ~$git push
http://username.github.io. 
Give it a couple of minutes for your page to show up—there will be a delay this very first time. In the future, changes will show up pretty much instantly.
Casiano Rodriguez León 2015-01-07