Typically you want the permissions to be:

    .ssh directory: 700 (drwx------)
    public key (.pub file): 644 (-rw-r--r--)
    private key (id_rsa): 600 (-rw-------)
    lastly your home directory should not be writeable by the group or others (at most 755 (drwxr-xr-x)).

I am assuming that you mean that you have to enter your system/user password each time, and that previously you did not have to. cdhowie's response is assuming you set a password/passphrase when generating your keys, and if you did then as he says you will have to enter your password every time unless you use an ssh agent.