virtualbox.org

Hello,
I want to install a headless virtualbox on a ubuntu vps (guest=windows7). I want to make it highly secure (port blocking).
Is there a good tutorial out there for this? Thanks!

p.s.
If not, please tell me what I should read for this.

A good place to start is to read your VirtualBox users guide. It explains how to set this up. The ports are up to you.
You have several avenues that you can go down so read the network section (6) and the remote section (7) closely.

VPS means Virtual Private Server. VB doesn't work that well on a virtual environment. Since the 'Host' is Linux, I'm pretty sure the underlying base is Xen or VMware ESX(i). With Xen as base, it will never work because VB just doesn't like it. You can check this by verifying the kernel you're running with 'uname -a'. No idea with ESX, but that will probably fail too, but you will figure that out soon enough when you try.

See Virtualization inside a virtualizer, discussions too.