This is the directory structure you will end up with following the instructions in the Installation Guide. Note: You can use controllers or not, but is always recomended for big projects.
|-- ROOT
| |-- .htacess
| |-- index.php
| |-- src/
| |-- |-- OnePHP/
| |-- |-- |-- one_framework.php
| |-- |-- controllers/
| |-- |-- views/
| |-- |-- libs/
| |-- public/