See the downloads page for the latest source and builds (currently only Windows builds are provided - Linux and other OS users should be able to use the FreePascal Compiler from their distro's repository to build a native version for their system). Make sure you download the ol-win32-bin-xxxxxxxxxx.zip file.
Running Outliner Lighto with a new outline file (or just running it for the first time) will create a default outline with a tutorial on using it. It is recommended to read and follow this tutorial. Beyond that, Outliner Lighto comes with a set of manpages for UNIX systems and a PDF version which you can find in the downloads page for other systems.
A lame attempt on making a screencast for the program can be found at YouTube. Yeah it sucks, but this is all i've got for now :-P.
The first view of the default outline
Showing tickable nodes (for todo lists, etc) and automatic percentages