My favorite places to buy fish in Seattle are Wild Salmon Seafood Market, at Fisherman's Terminal next to the Ballard Bridge, and Mutual Fish on Rainier Avenue South. They both sell very high quality seafood and offer shipping. Good fish can be pricy. Ask the fish monger to help you select a good fish that ships well, and is reasonably priced.

I don't know of a local source for carp roe but you might be a good alternative from Seattle Caviar Company:

http://www.caviar.com/

You also might try this place:

http://www.bigjohnspfiseattle.com/index.html

Seafood City at southcenter is the mother of all Asian fish markets. Anything that can be done to a fish can be found there, including fried to order.

It is not within the city limits but, bus service there is easy. If you have not been there, you owe it to yourself to make the trip at least once. It is a truly amazing store.

Unfortunately, I don't know of any fish market that sells fried fish in Seattle. If you call Wild Salmon Seafood market at 206-283-3366, they might know of one. There is one in Everett, but that's 45 minutes away. It's Waterfront Fish Market, 2831 West Marine View Drive, Everett. They have a fried fish stand right at the market. I hope this helps you.

Do you really want whitefish (a specific species of fish; around here it's mountain whitefish) or do you want white fleshed fish fillets which would include sole, halibut, etc?

If you just need white fish fillets then Costco has some good deals as did Uwajimaya last I checked. Talapia in volume can get pretty cheap. Right now the standard decent per pound price for talapia and cod is 5.99 (talapia) to 9.99 (cod). I've seen talapia as cheep as 3.99/# and cod at 4.99/#.

Safeway also has some good fish deals. The circular comes out on tuesday.

Do not fear the non-white fleshed fish. King and Atlantic Salmon are awesome though the only Atlantic you can find is the eco-unfriendly farmed type. Coho is OK (but just OK) and while I like Sockeye a lot it seems easy to screw up. Keta and Pink Salmon suck. Keta is being marketed as a eatable fish but I don't even like it smoked. S'ok in a chowder or cioppino but just.

Tuna is friggin great and you can get albacore here very cheap. It's white-ish... OK, it's kinda gray at times, but still good.

They sell only smoked whitefish, but the cheapest place I've found to get both fresh and smoked salmon fillets is Loki Fish. They sell three places: the Sunday Ballard Farmers' Market, the Ballard Market at 15th and Market Street, or off the docks at the Fisherman's Terminal under the Ballard Bridge.  They're considerably cheaper and it always tastes spectacular.

Even though whitefish is freshwater, you might want to go to the fisherman's terminal anyway. it's cheap and those boys are fun to talk to.

I've also heard that while most folks lean towards fresh fish, a fresher tasting fish is often sold frozen and that a lot of 'fresh' fish is really just thawed. 

Sushi is fairly bland. Not a lot of flavor, and what flavor there is is pretty subtle. Rice and vegetable mostly. Sashimi is REALLY bland and flavorless. That is, unless you're eating at a crappy place, and then both will probably taste fishy.

Every place I've been to that serves sushi and/or sashimi gives you soy sauce and wasabi (a japanese hot horseradish) with it. Those are the only things that'll really give it any strong flavor. Most places have wasabi in a tube (like toothpaste. Wasabi has the same consistency as toothpaste) but really good places have it fresh. Fresh wasabi is not as harsh as tube wasabi, it's much more smooth and mellow. But it's still nose-running-spicy-horseradish no matter what.

If you don't like the taste of fish, avoid tuna, salmon, and mackerel sushi. Go for eel instead. Eel has almost no flavor at all.

I personally find sushi to be a waste of money. I like food with really bold flavors and sushi has none of that. Plus it's overpriced for what you get. It's just rice and vegetables and a tiny bit of meat. What you're paying for is the presentation and novelty and trendiness and popularity. But hey, if you've never had it, you might as well try it. It's good to explore and experiment.

Try going to a conveyor-belt sushi place like Blue C in Fremont or U Village, with a friend who like sushi. Go at dinner time, rather than lunch, as there will be more of a selection. Watch the plates go by for a while before trying anything. Start with one of the veggie rolls to see if you like the general taste and texture of this kind of food. The veggie tempura roll is probably your best bet. It has the basic ingredients --rice and seaweed -- plus lightly breaded and fried asparagus and green beans. Dip it in a little soy sauce when you eat it.

After than you could try other veggie rolls, then get progressively more adventurous. If you like shrimp, try the shrimp sushi (it's cooked). This would introduce you to the standard fish-on-rice nigiri sushi, and includes a little wasabi horseradish, which is essential to the taste, but can come as a bit of a surprise.

The best sushi isn't really very "fishy" at all. The super-high quality tuna used in sushi is completely different from what you get in a can. That said, I like some of the more fishy stuff like mackerel. I also love the tiny salt-cured flying fish roe used in some rolls.

Sushi is wonderful. You've got a chunk of fluffy, sticky, fragrant rice, often wrapped by a strip of seaweed with a chewy, salty flavor (and maybe a touch of crispness). Add a core of cool cucumber, soft, mellow avocado, seared tuna, or just about anything and it's a wonderful meal, both in flavor and texture.

I like to have a little dish of soy sauce for dipping and then stir in some wasabi for a little kick.

Go to a sushi bar with a couple of friends who like sushi. Blue C, for example, is great because you can try a lot of different kinds inexpensively. Start simple (cucumber rolls) to see how you like it, and then work your way up to more complex concoctions. Any kinds you don't like, just pawn them off on your friends.

I'm not a huge fan of raw fish just because I don't think it has much of a flavor to recommend it, but I think that can vary from fish to fish. I find that even searing it just a touch can really bring the flavors to life. But that's just me.

Goodness Kristen!, go with someone who has some experience and eat.
The various cuisines of the world hold such wonderful tastes to explore.