I need to migrate the contents(domains,mail server and database) of my server to another. Can anyone help me how to proceed for this task.

Linux version-rhel5-source server
destination server-rhel5

contents of source server.
mail server-qmail
database-mysql
domains-5 nos.

I need to take a backup of the source server. Could you please tell how to take full backup of the source server remotely and put all its contents in another.

Thanks in advance
hartech