At first: Palermo is a realy historical city. If you're not sure about your trip: go for it, it's worth it.
And of course: stay at the quattro canti apartments :)
Ivan, Vincenzo and (i think his girlfriend, did I spell this right?) Juicy are nice hosts. The "Taxi"service from the airport was perfectly organized, the contact via the airbnbapp was smooth, the tips for walks and and the right places for typical sicilian food were awesome.
The apartment is modern, cozy and clean. Everything form there is just a few steps away.
Ask Vincenzo for the best arrancini in town. You wont be dissapointed.