Once you've copied the public key to the remote machine you need to put it in the .ssh/authorized_keys file (creating it if necessary) for each user you want to be able to connect as.
You need make sure the .ssh directory exists and is only
accessible to the user by using the command mkdir
~/.ssh >> chmod 0700 ~/.ssh
, while logged in
as the user in question.
then you can use the command cat ~/id_dsa.pub >>
~/.ssh/authorized_keys
(replacing ~/id_dsa.pub
with the path to the file you copied which contains public
key), as the user in question.