as for partitioning, you need a minimum of 4. assuming you only have one hard drive, hda, it might look something like this:
/dev/hda1 -- windows
/dev/hda2 -- swap
/dev/hda3 -- / (mandy)
/dev/hda4 -- / (suse)
for linux, you always need a swap partition, which should be around the same size as your RAM. i'm pretty sure you can use the same one for both mandy and suse though. there are many different partition setups for linux too, but keeping everything on one is the simplest. you may want to create separate ones for /home, /usr, /opt or whatever your preference is.