If you are running Ubuntu Desktop 10.04 on your host computer and want to use VirtualBox to virtualize the Ubuntu Server operating system that we are going to build, then you can follow these instructions. Or, you can just skip this blog entry and go to the next one about installing Ubuntu Server like normal on a physical machine. Below is a screen shot of the Applications > Ubuntu Software Center window. Open this window and search for "VirtualBox" and install it like you see below.
Then you can start VirtualBox from Applications > Accessories >VirtualBox OSE. You will see the window below, but will not have any VMs of course. Go ahead and create a new virtual machine using the "New" button and step through the wizard.
Once you have created the new VM, you can go into the storage item and add set the CDROM to point to your Ubuntu Server .ISO file so it will begin the installation process the first time you start the VM. I recommend doing this because it works well and allows you to avoid burning a CD with the operating system on it.
Now you are ready to install the Ubuntu Server 10.04 operating system.