If you are going to stick with real black powder and Pyrodex, I would recommend that you pick up a copy of the Black Powder Handbook and Loading Manual by Sam Fadala. It has a fantastic loads section, and has EVERYTHING you need to know to shoot BP. For $20, its a good invenstment.
The onyl drawback is that it needs to be updated to include 777 loads, and the newer in-line magnum muzzleloaders.