It says "fried pork rinds" on the package so I always figured that's all there was to it, but it's actually a three step process. Two different three step processes, really. One for if you've got a big wood fire going to roast the pig you stripped the skin off of and one for a kitchen.
Step one is a 30 minute simmer. If you're starting from the whole pig, the point is to soften the bristles so you can scrape them off. If you're using skin and fat sliced off of a prepared pork shoulder, then there's probably no real point to it. The top Google result for "chicharrones recipe", at tasteofcuba.com, leaves it off. They forgot to delete the 2 cups of water, though, so you can tell it was there in the recipe they copied. (They also left the Filipino-style condiment. Bit of a tip off there.)
If you're doing this over the fire pit, it's probably easier to keep the skin whole. Otherwise, slicing it into inch-wide pieces makes more sense.
Step two is baking the pieces at 250 or 300 degrees (opinion is divided) for three hours. Or just hang it an appropriate distance over the fire pit, quite possibly while still attached to the pig. Only a little of the fat renders, but they've browned a little and the fat softens as it cooks through which is important for the final texture.
Step three is deep frying for several minutes. The skin crisps and the fat puffs up as the moisture in it turns to steam. Theoretically, you should end up with a matrix of thin crisp fat surrounding air pockets. Not quite as styrofoam-esque as the industrially packaged stuff, but in that neighborhood. I had some trouble getting the pieces cooked through before the outsides over-browned. Probably my oil was too hot, but since nobody gave any instructions on how hot I was aiming for, I don't really know. These lovely golden brown chicharrones are gooily undercooked inside. I heated the oil back up and fried them for a couple more minutes. Also, a cut a slit in the side of each to make sure the oil could get in and do its work. I cooked them as long as I could before I was too concerned about burning and pulled them out. I think the result is about 90% there, but I'm not going to mess with them any more.
The result, once I've sprinkled them with salt, at least as good as the ones you can get at the corner bodega. Crisp with a series crunch on one side and a little chew on the other, good pork-fat flavor, really greasy. Much better than the supermarket sort and if you're going to eat something so very bad for you, it's best to make it worth your while.
I was wondering what to do with them beyond just snacking with beer. Looking around, I see that it's used in some stews, ground up and used as a condiment elsewhere, baked into cornbread. But the biggest application is in mofongo. I think I'll try making that.