Well, it depends very much on your own expertise. Some authors are well versed in Mathematica and are familiar with a large number of functions which ordinary people (like me, for example) rarely have met before. In those cases, one must go step by step, going back and forth from the on-line help browser. Sometimes one finds extremely clever solutions which simply take time to understand. And sometimes, fortunately, some of the authors are kind and generous enough to provide some guidance to less experienced readers. And, of course, you can pose specific questions to this community or other places like math group or stack exchange, and you might get the answer you need.