The QuickStart guide describes the standard, recommended and quick way to install the Nagare framework.
The NagareInstallation guide details the various ways and options to install the framework under Linux and Windows. Especially, read this guide if you want a developer installation of the framework.
The NagareUpgrade guide describes how to upgrade an existing Nagare installation.
Then, if you want to install the demonstration follow the DemoInstallation documentation.