Part 2 of the four part installation procedure for Nagios involves the actual install of the Nagios Binaries itself. Here we cover the download, and installation of the latest stable version of Nagios.
If you jumped directly into this article, its worth having a look into the installation and configurations of the Nagios pre-requisites at the link below
Nagios Version: Nagios 2.10 (at the time of writing this article)