No need for ginger in all fish recipes, certainly wouldn't hurt some.
As far as fresh v. frozen, if you aren't close to the ocean it's pretty much all been frozen. Some of it is kept that way and some is thawed and sold "fresh" in grocery stores. Perhaps you can get sashimi-grade in some higher end places, I never tried when I lived in the Midwest.
There's 5-ish types of fish to cook by my reckoning, not necessarily the absolute truth just how I tend to think of it.
- Darker, firm and oily fish like achovies, herrings, sardines
- Lean, white fish like pollock, rock fish, haddock, catfish
- Oily, medium colored fish like char, yellowfin, mahi mahi
- Lean, flaky fish like sea bass, red snappers, tilapia
- White, firm fish like shad, lake trout
The flakier the fish the more delicate your cooking should be, foil wrapped fish with herbs and butter is great and can be easily cooked indoors or out.
You can tailor that type of cooking to pretty much any preference or ethnic style you desire. Tilapia rubbed with a little olive oil and seasoned with S&P, dill, minced garlic, coriander, paprika and fennel makes a great Mediterranean-style dish that you can fill out to a complete meal if you toss some cherry tomatoes with rosemary and thyme in another foil pack or the same one as the fish.
Make one per person and a salad and you can easily feed a few people for low cost, fish can be quite affordable at your local grocer or market.
Heavier, meatier fish can be cooked almost like a steak.
Yellowfin tuna is great with a light marinade, something like oil, dijon mustard, lemon juice, garlic, lemon peel, and soy sauce. Marinate for a few hours, dry it off, toss it on the grill and baste in the leftover marinade.
Frying fish is another option, catfish and mullet are common in the southern US and are usually battered in corn meal and cooked outdoors. Midwestern fare is usually beer battered cod, walleye, and perch; catfish if you live near the Mississippi. A big local fish fry is an awesome event, really common in Minnesota and Wisconsin because of the whole Catholic fish eating tradition.
Frying fish while camping is another good option, you be hard pressed to find much better fish than freshly caught walleye battered up and served with a little lemon juice about half an hour after it was swimming.
Salmon is another category unto itself almost, lots of people have very particular preferences regarding how it should be prepared and the variation between all the Salmonids of the world is pretty significant.
Pacific and Atlantic salmon are the two biggest categories.
Pacific salmon are as follows, there might be a few more
- King/Chinook; Classic oily, deep red salmon
- Sockeye; Bright red flesh, usually ocean caught
- Coho/Silver; Similar to King but lighter in flavor and texture
- Pink salmon; Most common, often canned
- Chum/Keta; Not eaten in the US a lot, medium colored and low fat
I admittedly have no experience with Atlantic salmon, but as far as I know pretty much none are wild caught any more due to long term over-harvesting in Europe and North America.
There's a whole wide world of fish out there, so much variety in species and the hundreds of years of culinary history make it an awesome avenue to go down in your exploration of cooking.
Ginger is not necessary who ever told you that needs to be fried in it. As far as cooking frozen fish goes, I prefer letting it thaw out in the fridge overnight. Very watery fish fillets (Waleye, Tilapia, Pollock) tend to break down in water as well as being fragile. You could get away with (in my opinion) thawing heavier fillets such as Salmon, Tuna ect. in water without much hassle.
On that note, if you're just getting into it, try just a simple pan fry with lemon butter and rosemary cook it till it's white (or pink if salmon) all the way through.