You need to add entries to your /etc/fstab for each partition you want to mount. You'll also need to create mount points for each of them. To have partitions automatically mounted on boot, add "auto" to the options list (the 4th column) of the relevant line(s) in fstab. There's a guide to fstab here
. If you need more help, give us info about how your partitions are laid out and what filesystems they're using.