We visited Croatia last fall and spent a glorious week on Dugi Otok. We were driving the coast and took a ferry from Zadar. The tourist office in Sali helped us locate an inexpensive rental on the water (although our Australian neighbor told us they found their place on the web). The apartment was very comfortable and the island was very beautiful with lots of places to walk and swim and explore. I agree with the recommendation to visit Plitivica, but the nice thing about visiting an island is the chance to be in a more rural place and really, really slow down and relax.