There are several ways to go about this. I assume you've already installed vista.
1. Download GParted Live. It is a live CD disk partitioner. Use it to shrink your vista partition to whatever size you want (1/4 drive for equal space, maybe 1/2-3/4 if you use vista more). Leave the rest of the space open.
2. Install gOS. This requires burning the ISO to the CD and following the instructions. When asked where to install, choose the empty space you made in step 1. Tell it to not use all of it, just about 1/3.
3. Repeat step 2 for Tiny Core and Puppy.
Hope that helps. That's pretty general, but you asked a very general question. Post specifics if you get stuck.
Last edited by digerati1338; 02-13-2009 at 03:10 PM.