basics - follicle testing

So for those that are getting follicles checked with clomid, can someone break it down for me and explain it. Does more follicles mean, higher chances of multiples? Higher chances of pregnancy? What size is considered a good follicule? What happens to the smaller follicules? I get checked on CD 11 or 12, is that the same for others? Are there more testing that you all do that I can ask my doc to have done for me?