Some of my favs for scenic photos: Waikiki sunsets, Hilton Hawaiian Village hotel (absolutely beautiful grounds with parrots, flamingos, penguins, exotic birds, koi fishpond, etc), Diamond Head crater hike ( a little strenuous but beautiful overlook of Honolulu/Waikiki), Pali Lookout view of the windward (eastern) side, Byodo-In Temple near Kaneohe, Kailua beach, drive along the windward and North shore (some people like Jameson's restaurant in Haleiwa), sandy beach and Mokapu'u lookout (gorgeous scenic view of windward shore and rabbit island)-very dangerous surf though, Bishop museum and Polynesian Cultural center (somewhat expensive) if you're into history/culture, International Market Place in Waikiki, zoo and Waikiki aquarium are nice too. Some people take in a luau and hula show (but find a good one). Ala Moana shopping center mall near Waikiki is the best for shopping.
Hawaii can be somewhat expensive, the weather is not always sunny, and the traffic in/around Honolulu can be some of the nation's worst. Most people have the Aloha spirit if you're friendly, but there are always a few troublemakers to watch out for. The main thing is car break-ins at tourist sites, so don't leave your valuables, etc in the car (even in the trunk). It's not frequent, but enough of a problem to ruin some visitors otherwise paradise vacation.
Hope you have a great time here and leave with many fantastic shots and fond memories of a perfect vacation.