This guide is for installing it-core from DEBs. These instructions are based on Ubuntu, but should work on any Debian-ish distro.

This mostly command-line references. Be not afraid. It's just more concise and accurate than verbally describing graphic interfaces.

Step one

Install your OS. If your chosen distribution doesn't have good documentation for this step, choose a new distribution.

Step two

Install some required packages.
$ sudo apt-get install apache2 mysql-server php5 php5-mysql php5-ldap php5-cli php5-curl php-pear
The first command, sudo, changes to the root user. You will be prompted for root's password. The remainder installs a bunch of packages via apt, Debian's package manager. The install process prompts you to set up a mysql password.

Step three

Download and install it-core. Your filenames may differ slightly, depending on the version number.
$ sudo dpkg -i it-core-0.1.0-1_all.deb
$ sudo dpkg -i it-core-doc-0.1.0-1_all.deb
$ sudo dpkg -i it-core-fannie-0.1.0-1_all.deb
$ sudo dpkg -i it-core-is4c-nf-0.1.0-1_all.deb
These commands should be run as root. The base it-core package is always required. The it-core-doc package is just documentation and thus always optional. The it-core-fannie package contains the backend server; it-core-is4c-nf contains the lane point of sale system. Neither is strictly required, but omitting both wouldn't make much sense.

Step four

Start required services
$ sudo /etc/init.d/mysql start
$ sudo update-rc.d mysql defaults 
The first command starts the mysql database. The second makes mysql start automatically when the machine boots. Now do the same for apache.
$ sudo /etc/init.d/apache2 start
$ sudo update-rc.d apache2 defaults

Step five

Open a browser and go to http://localhost/it-core/. You should see at least a license as well as documentation, fannie, and/or is4c-nf folders depending on what you installed.

Further ideas (Production environment)