The Hawaii Audubon Society puts out a field guide. For a bird finding guide, I recommend The Birdwatcher's Guide to Hawai'i by Rick Soehren. Basically, you'll have lots of introduced birds near the resorts, water birds (including endemic coot, moorhen, and stilt) in lowland ponds, and endemic forest birds at high altitudes. I haven't been to Maui, but the premier spot for birders is Hosmer Grove and especially the adjacent Waikamoi Preserve owned by the Nature Conservancy. Those areas are good for 'Apapane, 'I'iwi, 'Amakihi, Maui 'Alauahio and with luck even 'Akohekohe and Maui Parrotbill. You have to make reservations with either Haleakala National Park or the Nature Conservancy for a guided tour to visit the Waikamoi Preserve. Haleakala is also good for Nene and Pueo (Short-eared Owl). Good luck!