Linux/RHEL

Red Hat Enterprise Linux (and it's open-source clone, CentOS) is a popular Linux distribtuion targeting the corporate server market.

Facts

 * RHEL and CentOS are effectively interchangeable when it comes to support instructions.
 * RHEL offers an extended support level for corporations, though when it comes to us we take care of our own servers.
 * RHEL uses the YUM package manager, and RPMs as package files.
 * RHEL 7 will remain supported as the main version until 2019.
 * SELinux is used as the primary Mandatory Access Control System.
 * Systemd is used as the primary initscript system.

Initial Setup

 * 1) Set up a as admin with sudo and ssh key, as well as any other users. Also set up a password (it's like a PIN, last line of defense against privilege escalation).
 * 2) * The private key created by Amazon should only be used in case of emergency by the effective owner (if other admins forget their passphrases or passwords).
 * 3) Change the hostname to the current one using hostnamectl.
 * 4) Set up the EPEL repository.
 * 5) Install Byobu, and enable it for all new users.
 * 6) Set up Nginx and also Server Blocks to make things easier.

RHEL
On Red Hat, you will want to utilize package subscription channels. CentOS's corresponding elements are EPEL.

https://access.redhat.com/solutions/265523

Databases

 * MariaDB/MySQL