You can start by reviewing the current product offerings from Microsoft and VMware for example. Microsoft offers Virtual Server and PC, while VMware offers VMware Server and Desktop, as well as ESX or Virtual Infrastructure platform.
Since you are interested in a pilot, I recommend downloading the free resources available from both Microsoft and VMware to get started. You can also tool around with other vendors. These are simply the ones that I use most often.
Topics that will be of interest to you are converting physical machines to virtual machines — a process known as P2V.
The best recommendation that I can provide with limited input is to simply get your hands dirty by playing with the technology. You should also invest in some learning companions such as <i>VMware ESX Server: Advanced Technical Design</i> by Ron Oglesby and Scott Herold and <i>Virtualization: From the Desktop to the Enterprise</i> by Chris Wolf and Erick Halter.
To be honest the first thing you need to understand is what you want from virtualisation? what is driving you towards this technology. is it consolidation, containment, high availability or less admin.
all these and more will help you decide on which way look a nd who’s virtualisation to look at.
do you want bare metal virtualisation or a hosted solution, mixed OS or single.
to be honest part of the process is to decide what you want from it then look at who offers what you need.
as a rule,
Hosted VMware, Virtuozzo, Microsoft
Baremetal VMware , Xenserver, Virtual iron
High availability VMware, Xenserver
Lower admin VMware
single OS Virtuozzo
Now thats just a start, work out what you want then visit the website and as Wrobinson says get your hands dirty and play.
hope this helps