Here is a quick key to the neighborhoods referred to in this guide:

French Quarter, Also know as "the Quarter(s)" or the Vieux Carré ("Voo-cah-ray")
—Canal Street to Esplanade Avenue, and the river and North Rampart Street

Treme, ("Truh-may") now famous thanks to the HBO TV series by the same name. You run into crews fiming all over the city for Treme and various movies.
—North Rampart Street to South Broad, St. Bernard Avenue to Orleans Avenue.

Fauberg Marigny ("fau-berg mare-ah-nee")
—Esplanade Avenue to Elysian Fields, and the river to St. Claude Avenue

Central Business District, known as the CBD or downtown
—Canal Street to Lafayette Street, and the river and I-10 expressway

Warehouse District, also known as the Arts District
—Lafayette Street to Howard Avenue, and the river and Baronne

Lower Garden District
—Howard Avenue to Jackson, and St. Charles Avenue to Tchoupitoulas.

Garden District
—Jackson Avenue to Louisiana Avenue, and St. Charles Avenue to Magazine Street

Uptown
—Louisiana to Carrollton Avenue, and the river to S. Claiborne Avenue

River Bend, also known as Carrollton
—Carrollton Avenue to Leonidas, and the river to S. Claiborne Avenue

Mid-City
—I-10 expressway to Esplanade, and N. Claiborne Avenue to City Park. Most of this area suffered greatly from flooding after Katrina but has been coming back in leaps and bounds.

Old Algiers, across the river from the French Quarter. A nice, free, ferry ride from the foot of Canal Street.

This map shows the differenet neighborhoods. The Preservation Resources Center has maps of these and other neighborhoods on their website, with information about the architecture and history. StayLocal also has some neighborhood maps and lists locally owned business by neighborhood.

Christy's Guide to New Orleans

Overview, weather, getting around, etc. | City regions defined | Fun stuff | Art and culture | The dark side | Kids and kids at heart | Dine like a local | Bars and clubs | Live music | For java heads