Well I use a 4" Rapala fillet knife.
I keep it sharp in one of those little red plastic sharpeners that have the x shaped ceramic stones housed inside.
A trick I discovered was to run my knife through either a slice of lemon or tomatoe, then run the knife through the sharpener.
A dry sharpener doesn't work, and water doesn't help much. The acids in the tomatoe or lemon must interact with the ceramic in the sharpener, whatever, you can feel the knife edge grab when you pull it through.
I fillet my Perch, cut around the rib cage, and then skin them.
It can be quite a job, taking at least an hour or so for 35 fish.
I use whatever coating mix.
Today consisted of whole wheat flour mixed with Shreddies which were ground up with a rolling pin while still in the bag. Added salt and pepper.
Broke 2 eggs into a mixing bowl, beaten lightly.
Dumped about 2lbs of Perch fillet into the eggs.
Forked them out 4 at a time into the bag of coating mix...shake shake shake.
Added them to a large frying pan with about 1 cup of sizzling Becel margarine, and a tablespoon of Olive oil.
Let them fry, observe the down side start to brown, use an egglifter, and flip them over, till they get a darker brown, careful not to burn as it will get smoky.
Serve on paper towels, or newspaper.
Oh, and if you like lemon juice, microwave a lemon that has been halved for about 30 seconds on high, and you will get 3 times as much lemon juice.