Hi Stephanie,
Lots to do in N.O. during the summer.
There's Essence Fest every 4th of July weekend. Tens of thousands of people flock to N.O. for some of the best music you can possibly imagine. Concerts at the Superdome/N.O. Arena and the Convention Center too.
Also, summer is a great time to get good rates at hotels. Typically, you can find one (depending on demand, of course) for less than $100/nt in a centrally located hotel (FQ or downtown).
The fishing is great too during the summer. So sports-persons can get their fill of The Sportsmen's Paradise quite easily. Charter fishing and trips to Jean Lafitte National Park are a couple of things that aren't on the usual tourist agenda that I'd suggest to check out during the summer
Have a nice trip! Bring your summer clothes!
-Gene