Boot and install 5 or versions of Linux including Slackware
 

I am trying to do the above. I have a 1.5 terabyte drive and a quad core box. If I remember correctly you need to use gparted or equivalent and partition the directories into the number and size you want. You don't bother installing Lilo or Grub until the end and then you install a distro that uses and configures the boot menu using Grub. In my case this would Ubuntu or Vector ( a Slackware front end ). Can anyone add anything or give me some pointers?

Yes you can use g-parted to create a partition for the journaling filesystem (EXT4) and the swap partition.

Make sure you allocate enough for your bootable file system and 1GB for the swap partition.

Every distribution comes with a partitioning manager so you can
use it to create your partitions. When done choose write to disk (HDD)

The bootloader; LILO for Slackware and Grub for most other distributions is close to the last thing that the installer will handle shortly before the installation is complete.

For Slackware choose the first option: Automatically Install LILO if that fails for any reason choose install LILO manually and pay close attention to what step your on or it could lead you to believe that your done when your not.

***IF you have another OS on your 1.5 terabyte you might want to write down the complete details to ensure during the install that you don't by accident edit those partitions***