on the client machine, generate a key:
ssh-keygen -t rsa -v 4096
This will create two new files in .ssh/ id_dsa and id_dsa.pub
paste the contents of id_dsa.pub into ~/.ssh/authorized_keys on the host machine. (note that ~/ refers to your home directoy on the host machine)
Open a new ssh session and test it. It should log you in automaticalyl.