The key.pub:s stuff should be inserted as a oneliner into ~user/.ssh/authorized_keys2
The best way is to:
Code:
mkdir -p ~user/.ssh
cat ID_DSA.PUB >> ~user/.ssh/authorized_keys2
chmod a+r ~user/.ssh/authorized_keys2
The need for a key varies on the configuration of the sshd. I myself have disabled passwords as an authentication method and a key is the only way to get in. If it has been set up out of the box, I doubt normal password authentication would be disabled, but you can allways check it at /etc/ssh/sshd_config
One thing to check would be that /etc/security/* (if it exists) dont have any restrictions for that user to log in. If this sounds odd to you, there probablky wont be a problem with those.. (: