Where can I find the best resources to learn about virtual server farms?

I am a computer security student. Last night in my network switching class, I received an assignment to give a presentation to my class in two weeks that explains the concept of "virtualized network server farms." (I'm not sure if this is the correct term, but it is the one my instructor used.)

Among the deliverables for my presentation is to provide an example of how it works; identify future ramifications of virtualized network server technology, how it may affect how we use networking and the Internet; identify companies or technologies that provide virtualized network services, and, finally, how virtualized network server farms relate to the subject of the course I am enrolled in (network switches).

I could stumble around the Internet gathering information, but I thought I might ask this community of tech professionals first to see if you could recommend some directed reference sources. I can do my own research. I'm just asking for some recommended sites, white papers, persons to contact, etc. that will provide me with credible resources that will allow me to get up to speed on this particular topic. I'll take it from there.

Thanks in advance for your assistance.