I would suggest trying the Maison Dupuy Hotel on Burgundy St. in the FQ. They have a nice courtyard, great pool and awesome restaurant (Dominique's) centrally located.

It's about 2 blocks off Bourbon St with relative easy access to the Fairgrounds for Jazz Fest.

Jazz Fest Shuttles will run from the FW area and downtown.
Tickets include admission and transportation.

Good luck!
-Gene