A lot of people do not like the taste of fresh water fish as they can taste a bit muddy.
Fillet and skin them and soak in milk overnight in the fridge.
Rinse and dry off, season, dip in flour and shake, shallow fry in a good quality oil. DO NOT OVER COOK.
Fish has no connective tissue so as soon as the flesh is set its cooked, any more and it dries out.
for a really excellent taste throw some salted butter in a hot pan and let it sizzle till in starts to go light brown, quickly throw some lemon juice in and shake, then around a teaspoon of fresh chopped parsley and tip instantly over the fish.