Go to store. Pick up a bag of House of Autrey medium hot (or regular) breading. Any decent fish breading will be just fine... they are a mix of cornmeal and flour.
Follow directions on the package.
I like to take my catfish filets and soak them in milk for 10 minutes or so. Shake off
excess, sprinkle with pepper, and bread well.
Put a half inch or so of oil in a skillet and heat to 375, or "fish" on a frying thermometer. Cook the fish about 2 minutes per side or until golden brown.
Be sure to let your oil return to temperature before cooking the next batch.
Don't crowd the skillet with fish; give them room to breathe.
Keep fish covered in a warm oven till done.
If you have an exhaust fan over your stove, use it.