All the Live CDs that I have seen are pretty self explainitory. You will want to use the manual option when you get to partitioning.
I could ask, if everything works why change? But I have at least 10 OSs on my main box at all times for play.
Right now I am on an old HP because I am resizing a partition on the main box.
The Live CD will be pretty automatic in all respects except for the partitioning. You are the only one that knows what kind of extra space you have. You do have the one partition that is big enough for another SMALL OS. If you want to do that just choose the option to use the largest free space when you come to the partition part. The CD will do the rest.
If you are going to try and put all those on at once you will need to wipe your drive and start over.
I would use sfdisk to partition the drive from a Live CD.
Your 4 partitions will come up in terminal and the menu will be on the bottom.
Just select one partition at a time and select delete until you have wiped them all out.
Select write and enter.
When that is done;
Select logical (this might be "extended")
Select linux native
This will give you one linux extended partition in which you can put as many logical partitions as you want or can fit in. You are limited to 4 primary partitions. An Extended partition is a type of primary partition.
Before you leave sfdisk I would create 1 partition at the end of the extended partition and that would be a small swap partition. This makes sure that you have a readable partition for the partitioner on the LiveCDs.
The rest of your partitions can be added as needed in the Live CD install partition section. This is where you will need to select "manual" when given the option in the installation proccess.
I would install the OSs in 1 partition apiece on that small a drive if you are multibooting. The OS you install last will be the one you are booting from.
When you are installing and get to the "where should we put grub" part (some don't have this option) make sure it is going on the partition with that OS. This way if you have boot problems you now where all the OSs have their own /boot/grub/menu.lst. Makes it easier to recover from terminal on a LiveCD if grub is somehow buggered.
As you install each OS will install grub and update it to include any other present OSs. At least in theory.
It is nice to have each menu.lst on the individual OSs so you can copy them to each other if you need to. The last one on should have all of them in its list.
If, when all are installed, they do not boot due to some error or other. Reboot a LiveCD. Pull up the terminal and as root;
sudo (or whatever)grub
grub find /boot/grub/stage1
(here you will get a list
choose the the last - say
grub root (hd0,4)
grub setup (hd0)
reboot and everything should work.
Most things numerate HDDs starting with "a" or "1" as in your boot from hda1. In grub this is expressed as (hd0,0) because grub does not use letters and starts with 0 instead of 1.
The main thing, the most important thing you must do to be successful at this is HAVE FUN.