This process will demonstrate how to setup a basic passwordless SSH keys. The keys that are created allows you to log into your shell server securely without having to enter your password or you want you can create a passphrase for added security measure but remember if you cannot remember your passphrase then you must recreate them.
Step 1. ssh-keygen -t rsa -b 2048
This creates both private and public keys using rsa with 2048 bit encrytion.
Step 2. ssh-copy-id -i /home/user/.ssh/id_rsa.pub remote_host
Ssh-copy-id is a script to connect to the remote host, copy the id_rsa.pub into the users .ssh folder and give it the correct permissons.