I have been writing for Coastal Angler magazine in central Florida since 1999. Sorry . . . you can't fool me. I strongly suggest to do your own fishing. There is good fishing everywhere, if you know where to look. I like cod and monkfish, so I will buy them in a market. You can't catch them around here. However, I get a twinge of conscience, because commercial fishing as we know it is very destructive. Sure there are limits, now, but they are too lenient for the condition of the stocks.
Anyway, knowing different fish is like knowing different kinds of wood. I suppose there are already books available with pictures and descriptions of texture, grain and flavor. I have a couple of hubs about fish and fishing. We don't like to promote our hubs from here, but you know where to find them. It may take an effort. They don't always show on the front page.
I will say this. Tilapia is a trash fish. It has more omega6 than bacon. It is bad advice to serve it to a heart patient. Farm raised fish and shrimp from out the US are suspect because of the water quality, feed, chemicals, and handling practices involved. Wild caught is always better. The fish have a varied diet and get plenty of exercise in cleaner water.
Buy your fish from a reputable seafood market or grocery store. If it smells fishy, put it back. Maybe even tell the clerk. It should smell like the ocean or a lake.