Best Practices

Very new to this whole hyper-v stuff and DMZ's

So I have my Hyper-V Server 2012 r2 Core setup on a physical machine on my Workgroup Network.  Managing it from my Win8.1 Pro machine.  Everything seems to be working.

I have created some VM's for lab testing.  1 Server 2012 r2 for my DC and a couple of Win 7 machines.  At the current time, I do not have them connected to any adapters because I would like these to be on a separate network from Workgroup for testing.  I would like however to be able to do patching. Currently my Hyper-V Server 2012 r2 Core has Internet access through my Workgroup network so I can patch it, but how would I go about, if possible, to allow my (DMZ) area to be patched?

I realize that I would at least have to create some virtual switches, but not sure how to configure them to allow my DC server and test machines to have internet access for patching?  One thought is to install a WSUS server to communicate with net to download patches from MS and then allow DC and test machines to get the patches form it?

I have done this kind a scenario with to different routers with internal and external IP's to create a totally different domain/network, but not sure if this would be the same if possible.

Any help would be greatly appreciated as usual.