Stereo Wiring Blues

So I’ve a pretty decent stereo receiver (a Denon something or other — I can’t recall the exact model, but it does what I need), a speaker system to match it. Within the last few months, I’ve added some new components, namely an Xbox at christmas and several months before that, a digital cable terminal.

So now here’s the dilemma: I’ve only 3 digital-audio input on this thing. Two are optical, one’s the co-axial. Currently, only the DVD player is using it, bringing in on the co-axial. If I understand correctly, the SPDIF out on my Cable box can only use the co-ax connection. Which would leave the two optical connectors for the DVD player and the XBox. Would I notice the difference? I don’t know. And would this work? I don’t know. I spent a good 45 minutes last night making mental diagrams of all the connectors (further troubled that my neither my TV or VCR has any digital connectors — stereo & video-in only), and ended up thoroughly confused. However, I could purchase a pair of optical cables and one more good-quality co-ax. But is it worth it?

Can anyone who knows point out a good ‘ack! i need to hook up all these components and I’m a moron’ site that might explain the ins and outs? Or you know what would really rock (and maybe I should write this), there should be a site that has little flash diagrams that would help me do this (like a connect the dots type thing), which could then be resold to the various companies as a customer service tool. Yeah. Cause I know I could use something like that.