At summer cookouts, it seems that just about anything from fish to fowl can be tossed onto the grill.

Health-conscious chefs increasingly are choosing fish to grill because it is lower in fat than many other meat options, and some types such as salmon and mackerel provide heart-healthy Omega-3 fatty acids.

Fish is one of the most versatile foods you can prepare. Its mild flavor and firm texture can be matched with a variety of flavors. Grilling is one of the simplest and quickest ways to prepare fish, but novices sometimes are hesitant to try it, said Judith Fertig, co-author of "Fish & Shellfish Grilled & Smoked" (Harvard Common Press, $15.95).

But with a little practical advice and practice, it's easy to become a pro.

"(Fish) tastes really wonderful on the grill, and you can have dinner in under 30 minutes," Fertig said.

Beginners should "start with a fish that is forgiving - and doesn't fall apart easily," Fertig said. She recommends farm-raised catfish, which has a mild flavor and firm texture. "(But) there is a wonderful variety of fish in all parts of the country," she added.

Any firm-fleshed fillet, steak or whole fish is suitable for grilling. Other choices include salmon, tuna, shark, halibut, monkfish, striped bass, bluefish, black sea bass, mahi mahi and swordfish.

Shellfish also are delicious cooked on the grill. Shrimp are the best shellfish to begin with, Fertig said. You'll need perforated grill rack or skewers, so they don't fall through the grill rack.

When grilling fish, begin by rinsing it in cold water. Then pat dry with paper towels before marinating, seasoning or cooking.

A spicy herb rub or salsa should complement but not overpower the delicate taste of seafood.

"It's really hard to overseason fish. When it's cooked on the grill, a lot of the rub or marinade burns off," Fertig said.

Marinate fish briefly, only 15 minutes to an hour. Longer than that and the fish flesh begins go break down and become mushy, especially if the marinade contains acidic ingredients such as lemon juice or vinegar.

"You don't want to end up with ceviche," Fertig said.

When ready to grill, make sure the grill grate is clean; then oil it. Oil all grill equipment and utensils that will touch the fish.

Fish and shellfish are at their best when grilled quickly over a hot fire. Fertig prefers hardwood lump charcoal for flavor, but gas is fine.

"Sometimes you just don't have the time to make a fire," she said.

Grill the fish or seafood for only a few minutes, until just barely cooked through.

"If you're cooking a fillet, start with flesh side first," Fertig said. That way when you turn it, the skin will help hold it together.

It should be well seared, but be careful not to overcook delicate seafood. In general, fish should be cooked until it flakes when a knife is inserted into the flesh, about 10 minutes per inch of thickness.

As your confidence grows, so will your fish choices and grilling options.

BUYING FISH

• Go to a reputable fish and seafood market with knowledgeable employees;

• You can tell whether the grocery store is into its seafood department. If it's not, go somewhere else;

• Fresh fish has a good texture and no overpowering fishy or ammonia odor;

• Whole fish should have bright, clear eyes;

• Sometimes freshest is frozen. Look for fish labeled "frozen at sea" or "FAS." That means it was frozen on the boat shortly after it was caught;

• If you buy frozen seafood, make sure it is still frozen when you buy it. If it has been thawed, you don't know how long it's been in the case;

• Be flexible. You might have your mind set on flounder, but when you get to the market, it's not fresh. Be willing to make an adjustment. A table and recipes in "Fish & Shellfish Grilled & Smoked" suggest substitutions.

TOP TIPS FOR GRILLING FISH

• Select only the freshest fish and shellfish;

• Handle fish and shellfish carefully and safely;

• Marinate fish and shellfish for only 15-60 minutes;

• It is preferable to leave fish skin on when grilling;

• Grill over a hot fire. Hold your hand 5 inches above the heat source. If you can hold it there for only two seconds, your fire is hot;

• A general rule is to cook fish 10 minutes per inch of thickness, 5 minutes per side;

• Test for doneness by making sure the fish and shellfish are opaque and somewhat firm. Fish that is done will just begin to flake when tested with a fork.