Setting up a staging server

Since I’ve had issues with bugs affecting important features of my community, I’m considering to setup a staging server, as suggested by:

I assume it’ll be a little more complex than this, though. It would need its own (sub)domain, for a start. And what about email? I’d like to test email functionality, but obviously my members shouldn’t receive any emails from a staging instance. There are probably other things to keep in mind as well.

Is there a tutorial for how to set up a staging server from a backup?