Tons and tons of info around about how to strop. try doing some searches here and maybe google or something.
Anyways, the basic jist of it is that you lightly drag the blade across the leather, spine first, and let the natural silca in the leather (as well as any stropping/polishing compound you rubbed into the leather) to gently polish away imperfections in the edge. It is really very simple once you try it.
Edit: I've had mixed results with speed vs. pressure. Some blades seem to like a slow, steady, even stropping motions while other tend to benifit from a quicker, less precise technique; I don't know why. As with any other sharpening method, experience and experimentation are the only ways to find what works for you.
