I have checked the tutorials and found them very useful. However i'm using Windows Server 2012 R2 so there is a little tweaking to do. I got my lab to work fine with Windows 2K12R2.
I'm wondering how to update the virtual machine since in host only mode i have no access to internet. It's not very important right now, i've switch all of my virtual computers to bridge mode and updated them before adding the Active Directory role.
Try to assign 2 network adapters to all your VMs. One adapter for internal communication (Host Only), An another for internet purpose (Bridge Mode). Disconnect the bridged mode adapters, whenever not required.