Skip on the gelatin. There are easier ways to clarify.
I use Whirlfloc in all my beers except those containing a good % of wheat. Each tablet costs about $0.20.
I then make sure that each beer sits at fridge temps for at least 2 weeks before serving.
Those two things alone lead to crystal clear beer!
If you have your heart set on gelatin, check out this thread: http://www.homebrewtalk.com/f13/how-...inings-129881/