interesting thoughts on that topic can be found here. after all i thinks its good to know how to use it.
ssh-keygen is the tool of choice.
-t sets the prefered keytype and
-b the size. some things to consider choosing the type are listed here. so after all
ssh-keygen -t rsa -b 2048
does the trick. you'll be asked for passphrase (which you'll be asked for from time to time) and that's it. don't forget to check out the ssh-keygen manpage for all the gory details.
ssh-copy-id -i ~/.ssh/id_rsa.pub user@remote-system
normally you just have to set the following sshd_config options:
# /etc/ssh/sshd_config PasswordAuthentication no ChallengeResponseAuthentication no UsePAM yes
and don't forget to restart your sshd.