Some things to know about when you are going to start prepping fish. Whenever you get a piece of fish, you want to make sure its fresh. You can always check the eyes to make sure that they are nice and clear. That's always a good indication. you can also check to make sure that the gills in the neck are really vibrant and colored. Nice reds or oranges. Nothing that looks to brown, faded or even grey. You also want to make that it smells fresh. Which means that it doesn't have any "iffy" smell or anything that might be a little funky, maybe a little questionable. It should also feel kind of smooth to the touch. Even a little slippery, but not necessarily gooey or slimy.
When you get your fish and it hasn't already been gutted or scaled, there are some things that you can do. If you are dealing with a fish where you like the skin, you want to scale it. That is definitely something you want to do. You can always take the back of a knife, you don't ever want to use the blade because you don't want to cut into the meat. You can always use the back of the knife and go against the actual scales. If you go with the scales, you are not going to get anything done. Starting at the tail and moving towards the head, just using using a bit of a brushing motion, you can actually clip off a lot of those scales.
When gutting it, there's two techniques. One of the more preferred techniques is to make a little incision up by the gill or even a little under the belly, but don't go too deep and you don't want to stab. If you do that, you could rip up some of the liver and the stomach. And it is a filtering system, you don't want that stuff to leak and get into the meat and get kind of nasty. What you want to do is just enough to break the skin, get your hand in there and be able to pull all of the guts out and you will see that it will almost come out in a little sack and you can just cut it and clean that out. Once you have the scaling and the gutting process done you're pretty much on your way to being able to clean up and fillet your fish.