SSH Key Authentication ReferencesSSH Key based authentication
A simple explanation and guide to the basics of key authentication. If you hit enter without using a passphrase, then you are strictly using key authentication as the only authentication.
SSH Keys (archlinux Wiki)
This one is more intense and has more explanation on how key authentication works. It includes options for added security and strngth. About a 1/3 of the way down, there are a couple of methods, including a "simple" method. I have never tried to use the ssh-copy-id command, but, it looks like it could help simplify things.
11.2.4. Using a Key-Based Authentication
This is Red Hat's official documentation. It is considered "THE" documentation for our class other than the Academy.
SSH Key-Based Authentication on RHEL6
This is specific to SELinux relating to your key authentication setup. I doubt you will have this issue, but, it is good to know.