how to create authorized keys

I’m following along with this tutorial http://toroid.org/ams/git-website-howto about how to use git to deploy to a remote server with a simple command like ‘git push web.’ The article has the following paragraph

“I assume that the web site will live on a server to which you have ssh access, and that things are set up so that you can ssh to it without having to type a password (i.e., that your public key is in ~/.ssh/authorized_keys and you are running ssh-agent locally).”

In the .ssh directory on my local machine, I have

“id_rsa id_rsa.pub key_backup known_hosts”

i.e. there is no ‘authorized_keys’

Can anyone explain how I might create authorized keys for this to work? thanks in advance