How do I Creating Virtual Machines on an Ubuntu Server that I am running through VMPLAYER

How do I Creating Virtual Machines on an Ubuntu Server that I am running
through VMPLAYER

Downloaded ISO for the Ubuntu 12.04.03 server. Run through VMPLAYER set up
completed successfully. Now what I don't understand is how do I set up
other Virtual machines (like windows 7) on this server and keep that
virtual machine host-only. Is that possible?