Corn tortillas are a lot easier to make than flour. A simple recipe like a couple of the ones above are the best, but for me lard has always been the trick. They get nice "blisters" on them with some lard. You don't have to use a lot, but they do taste that much better with at least a bit of lard in the flour mixture. And I agree, it makes the rolling out of the tortillas much easier, too.
Everyone is correct: they are more difficult to keep in the frig than store bought. But then they don't have preservatives in your home made ones either.
Happy cooking, Marty.