Have a look at Dar (http://dar.linux.free.fr/)
, and the GUI frontend Kdar.
Mount all partitions you want in the backup (for this example, one distro). Build your script to start at the root of the filesystem (/), and all mounted partitions in that filesystem (/, /boot, /home, /usr, or any others you may have) will be included in the backup.
Convince yourself it's all there by listing the backup. The TUTORIAL tells all. What goes into the script, how to list it, how to restore, etc.
Control Center - yast2 - software - install and remove. you may have dar and kdar on installation cd/dvd.