The void cube has no centres and a big gaping hole where the normal cube mechanism goes. It's quite hard to imagine how this might work until you hold one in your hands and see the mechanism - then it makes perfect sense.
You can pretty much solve this as though it were a cube with centres. Strangely, by ignoring the centres, you can get yourself into a little pickle. Some of your algorithms might seem to not be doing their job as normal. This is a parity error that comes about as a result of the cube not being in the state it normally is when you do that algorithm. This is because your normal algorithms sometimes affect the centre pieces. Because there are none on the void cube, you tend not to notice until you're stuck. So even though there are no centres, they're still there in one sense.
The void cube in this picture is of reasonable quality but doesn't turn like a decent speed cube. It's something to collect if you like the look of it but not much more of a challenge than the cube.