Bars
Here is a great itinerary for Frenchman street on the East side of the French Quarter (http://www.nola.com/bar-guide/index.ssf/2012/07/new_orleans_bar_guide_2012_fre.html)
Snug Harbor - old school music venue...an absolute must. Winston Marsalis' brother plays there along with a few of the Neville Brothers now and then (http://www.snugjazz.com/site/)
Jean Laffite's Blacksmith shop on Bourbon - it is the pirate's old Blacksmith shop and one of the oldest bars in the U.S.
Napoleon house on Bourbon
Pat O'Brien's - check out the piano bar and have a Hurricane.
Tropical Isle - have a hand grenade (the max I had was 3 and I was done for the night)
Preservation Hall - Jazz
Funky Pirate - blues and a variety of music
Haunted Tiki Bar, best Halloween-decorated dive around (cash only, great jukebox)
Pravda, best Communist-themed bar that serves absinthe
Carousel Bar in the Hotel Monteleone. Jimi Hendrix stayed here in like 1969 or something
BMC at midnight or anywhere where there is a good brass band playing.
Another list of great bars in the French Quarter it will help you find what you are in the mood for. (don't share this with anyone, instead, just surprise everyone with your bar knowledge when making recommendations on where to go next http://www.nola.com/bar-guide/index.ssf/neighborhood_french_quarter/index.html)
Now you wished you had more than a day.... This came from a local who grew up in the BIG EASY..