I grew up in Nebraska, my Grandfather's sister fried carp we caught on limb lines. Moved to Oklahoma when I was 16, found out you can't eat them. 40 years later, my son shot some this spring, and we cooked and ate them. Still taste like the ones I used to eat. Personal preference, but they beat channel cat like a drum.
For prep, I fillet them, bones and all. Then skin the fillet and remove the middle section of dark meat. The intermuscular bones come out then, too. make sure to keep it cool (immediately is best) until you cook. I fry them, just because it is easy and quick, but they can be fixed like any other fish.
For most fish, I find that they are like any game. If you wait for a few warm to hot hours before you gut and skin a deer, the quality will be about like fish that hang dead on a stringer in warm water for half a day before cleaning. I don't need any, thanks.
I raise several kinds of fish, and did some blind taste tests a few years ago. Channel cat, grass carp (not the common carp mentioned above), and buffalo. Cooked all three fried, smoked, and grilled. Preference rank were tie for grass carp and buffalo, with catfish left on the plate. The consumers were amazed when they found out what they ate. Cooking method made no difference. I'm still alive, so it must not have been all bad.