Home Network Streaming for Dummies?

[nickc]

I allowed myself to think that I'd more or less got my head round it, but having just read right through 'The control app thread' (on this sub-forum) I realise, 1: I've barely got hold of the basics and 2: a lot of the trouble shooting I've had to do over the years is not as specific to my particular setup as I'd thought, but perhaps more of a universal experience for those of us trying to achieve a reliable, stable and flexible home audio streaming network environment for high quality listening. My own limited understanding has come from all sorts of different sources - some of the most useful on this forum - but I'm wondering if anyone knows of a good (online) guide that covers the essentials, especially the interaction between servers, controllers and renderers, without proseletyzing unduly for a particular brand or ecosystem and providing enough technical explanation to make sense of the underpinning processes without getting bogged down in the minutiae.

That leads me to a more specific supplementary question which I probably wouldn't need to ask if I had read such a guide: is it possible to / how does one get a rendering device with both ethernet and HDMI inputs to render the signal from the latter rather than the former? Eg In one setup I have MinimServer on a QNAP NAS sending to Volumio on a RPi with a Hifiberry DAC, the latter connected to an old Arcam amplifier. On another setup MinimServer sends to an Arcam AV receiver (SR250) via an ethernet cable and the Arcam's internal network streaming capability. But what if I wanted to connect the RPi directly to the SR250 by HDMI, bypassing the Hifiberry DAC and utilising the Arcam's (superior??) onboard DAC? I use BubbleUPnP, btw, as my controller of choice.