When it comes to food, of course, this town is one of the foremost in the land. Just know that there is no simple guide because there are as many disagreements as there are tastes. But know that the food is important because of the mix of French, Spanish and black recipes you find in the Creole and Cajun cusine.
A special note: a local invention -- and favorite -- is the po' boy sandwich, hardly the stuff of the haute gourmet but definitely worth trying. It's roast beef, dressed with a rich gravey, lettuce and other garnishes and served on hot, thick bread. The place to try it is called Parasol's (2533 Constance) after a tour of the Garden District. While you're waiting for your meal you can talk about Alabama football, and whatever politician is in the news, with the good ol' boys who frequent this Irish Channel joint for a sandwich and a couple of Dixie beers.
If you have to stay downtown you can still get an excellent po' boy (but without the seediness) at Mother's (401 Poydras) in the business district.
Then there is the long-standing dispute over who serves the best New Orleans-style brunch of eggs sardou and a gin fizz. In the Quarter there's Brennan's (417 Royal) with a lush courtyard and subdued atmosphere. In the garden district, another wing of the Brennan family operates Commander's Palace (1403 Washington) out of an old, shocking-blue mansion. They have similar menus but the Palace also serves up hot jazz with its eggs hussarde. Both are pricey and theefore can be disappointing.
Some other New Orleans places to consider (in descending price scale):
Le Ruth's (across the river in Gretna): The crabmeat St. Francis, onion soup and fresh trout are fantastic, though the waiters can be a little green. Although it can be over priced, the redfish and the other dishes are worth it. Be sure to make reservations before you get to town.
Antoine's (713 St. Louis in the Old Quarter): Go, if only for appetizers. In this, the grand eatery that invented oysters Rockefeller, you will find an array of devilish seafood concoctions, including oysters Ellis, Beinville and Creole gumbo. Besides, it's about time you learned that Rockefellers are not made with spinach.
Pascal Manale's (1838 Napoleon): Barbecued shrimp are the specialty here, and you've got to learn the secret of prying them open first. Don't wear light clothes and expect to lose a little dignity.
Acme Oyster House (724 Iberville, in the Quarter): They'll teach the most insecure Northerner how to shuck and eat Louisiana's best oysters on the half shell, and get you a cold beer to boot.
The Camelis Grill (626 S. Carollton, of the St. Charles streetcar): A late-night linoleum diner with linen napkins! Always packed, often with college kids from nearby Tulane, it serves terrific "dressed" burgers, omelettes, and almond waffles. An American Graffiti classic: spunky, funky and tasty.