S/PDIF is a connection technology that streams digital audio. It manifests itself in several different physical connections: an RCA jack, an 1/8" mini jack, a optical input and output (the output is the one that's glowing. don't stare). Normally, you connect from one to another of the same type but there are adapters available to convert between them since the underlying data format is the same.
Connecting the Voiceworks to a mixer depends on the exact mixer you are using and physical layout of your setup. If the mixer is right next to you, you can just run a couple of 1/4" phone cables from the Voiceworks outputs to the Direct Inputs on a couple mixer channels (or one stereo input on the mixer).
If the mixer is on the other end of a snake or is further than 20 feet or so from the Voiceworks, you'll want to connect the outputs through the snake or mic cables to balanced mic inputs on the mixer. The Voiceworks only has 1/4" phone connectors for outputs but, thankfully, they are balanced so you can just buy adapter or cables with TRS (tip ring sleeve) 1/4" phone connectors on one end and a male XLR on the other and plug it directly into the snake or mic input on your mixer and still be balanced. With balanced cables, you can run wires a VERY long distance with low noise and excellent signal quality. Not sure why they keep cheaping out on the XLR connectors but it's a pain in the ass. The new VoiceLive2 finally includes XLR outputs.
I have a Motu Traveler mixer/computer interface
in my gig rack that has one S/PDIF input so I use that to connect the Voiceworks. Saves me two input channels and as a bonus, the audio quality is perfect. One negative is that you have to use the S/PDIF as the clock source for the interface. There is a setting for this. If you are interfacing with a computer or other device via ADAT you'll need to slave it to the interface which is slaved to the voiceworks. The voiceworks shows up as a stereo pair on the computer. All digital so it's a good golden channel