[Zope] Best way to run multiple sites in one Server

Well, it's a sys admin newbie question ;) I have just been handed over a server with some sites in it (not many :) ). I wonder what is the best way to run multiple sites on one computer? I heard some ways: multiple zope server running in simultaneously, using virtual monster, using PCGI, using Fast CGI. What are pros and cons for each way? What is the best way to run multiple zope sites in one computer? Are there any reading materials I can read about this matter? (I think the old Zope Administrator Guide is not enough :) ) Thanks for your help. -- mico@intermatik.co.id -- www.intermatik.co.id ICQ #12521756