Rsync with script

[Sarabjit Singh]

Hi,
I am trying to mirror a server every night using rsync. I have to backup
multiple directories and multiple individual files. I also want to use ssh
as transport.

The problem is that I cannot get ssh to work without asking password for
each step. I tried the public key thing but it doesnt work.
Can some one give instructions for a layman like me.
Also I want to know how to pass argument to sync multiple files and
directories by running rsyn just once.

I am running Redhat linux 7.2.
Thanks