Basically, much of what was stated by others above are wonderful for kids. Zoo, aquarium (also has Imax theater), mardi gras museum, children's museum, walking around in french quarter (cafe du monde, riverwalk, steamboat rides, farmers market). Please check out nola.com as it is the best guide for touring the New Orleans area and getting insite into all the city has to offer. I would tell you to visit city park (children's area there with small child rides) and look into leaving the city (about 15 to 30 miles out of town) for a swamp tour as you will always see aligators and many other wildlife. There are many wonderful tours given around N.O. which the brochures will be located in you hotel or you can find info on nola.com. Mardi Gras was just 4 days ago so you won't have to worry about that unless your visit will be in Feb. 2009. We also have many other festivals in N.O. throughout the year and those can also be listed in the website (we are coming up in the next month for the French Quarter festival and then the Jazzfest at the end of April beginning of May). If you have a rental car you may want to ride out to the lakefront and take a look at the causeway bridge (it's the longest bridge in the world at 24 miles). There is also a riverboat that will take you to the National battlefield in Chalmette where the battle of N.O. happened. The land there was completely flooded during Hurricane Katrina and there is a small welcome center which plays a short documentary about the war.
You didn't say how old your kids were or what time of year you planned on visiting. If your kids are almost teenage years then there are a haunted mansion/places tours you may want to think about as well as a cemetary/voodoo tour which really gives an interesting look in Louisiana history. We also have several different museums such as the WWII museum (if kids are too young then you may want to skip the museum as pictures/films will be graphic). There are also several other museums scattered throughout the downtown area as well as the Art museum located inside of city park. If your planning on visiting during the months of June through September please, please, please be aware that our humidity will literally suck all the oxygen out of your lungs. Sweating is the only agenda everyone walking the streets has during our summers and a lot of tourist who come during that time find they have heat exhaustion from not drinking enough water so please keep this in mind (bring fan misters, buy plenty of cold water and try to keep out of the sun from 11 till 4, bring hats and sunscreen). Also keep in mind that we get about 60 inches of rain in a year so sometimes we have showers that last 20 to 30 minutes and at other times we have thunderstorms that can drop 4 inches of rain in 3 to 6 hours and the streets will flood so I suggest carrying rain panchos or small umbrellas.
N.O. and the surrounding metropolitian areas were all deeply affected by Hurricane Katrina and will be recovering for years to come. Many areas are still barren with broken homes and no one around (stay out of these areas). Most tourist areas are fine and clean. Stay away from the dark unclean areas and do not wander into Armstrong park too early in am or late in pm. Also avoid St. Claude area by canal street (mostly when it is dark). Stay in areas where street lights and several people can be seen walking around and you should be fine. Let me know if you have any other questions. You'll have a wonderful time just do a bit more homework and be aware of the weather condition.
