I'm no painter, but I do feel that I'm definitely the target audience for GW's Contrast line. Though I'm not a total newb to painting, I don't do it often enough to have consistent and practiced results. So I picked up some paints, some primers, and grabbed a variety of models to mess with.
My pictures are not great, and sometimes they look like there is bare metal spots when there aren't, just due to glare issues...but hopefully they give you some ideas how the contrast paints work on different models from a newb's perspective.
These are all one coat pretty much, nothing more...