A very good tool to know about is the Virtual Network Editor. It lets you configure your virtual networks. You can add up to the full 20 virtual networks that are possible and then define their numbering schemes, create a DHCP environment for them, and so on.

You can even make your very own intranet:

This network configuration power isn't the only reason I'm pointing out the Virtual Network Editor. There's one little inconspicuous button that may be a lifesaver for you even in ordinary NAT and bridging scenarios: Restore Defaults. This little button erases all of the custom configuration and added networks and restores the out-of-the-box defaults. There is a long list of reasons why the virtual networking will just stop working altogether, but we won't cover any of that. Just remember this option as the nuke-the-site-from-orbit option for cleaning up a convoluted and broken virtual network.