Okay, that looks like the same PSU as in Arthur's links. Think the wiring diagrams are pretty straight forward
here. You are going to need a
logic level shifter (also available on eBay) to convert from Smoothieboard's 3.3v logic to the 5v logic of the PSU. It's all documented in the linked guide. Though I do think they have the PWM line drawn wrong, it should be going to IN on the PSU.
Oh, and when you attach pictures it would be better if they were in .jpg or .png as those are viewable full-size inline, .bmp requires that they be downloaded.