I used a lee loader, the kind you use with a mallet. Basically, it comes down to using a different pin for punching out the smaller pistol primers.
As far as loading, I gather a pressure appropriate load, as Mark has said, measure my powder with my scoop from my lee loader, pour into my brass shell, I then push in my nitro card, and over powder bushing. Depending on how much shot I'm using, I'll push in 2 bushings. This is all done with tools provided in the lee loader.
Next comes the shot. Again I use tools provided in the lee loader. Pour that into the brass shell. Next, I use an overshot card. I push that onto the shot, and use a very small bead of superglue around the ring of it to hold it all in place. Done and done.
Takes some practice but once you get the hang of it, then it goes faster. I use lead shot and the brass cost me about 1$ each.
There is some good info online. I find it's a good way to keep my old girl shooting.