Combine flour and salt in a food storage bag or paper bag; add chicken pieces, a few at a time, and toss to coat well. Reserve remaining flour mixture.
Grate 1 teaspoon of peel from orange; reserve. Peel the orange and separate into sections. Cut each section into 4 pieces; set aside.
Heat oil in a large skillet over medium-high heat; add chicken pieces and brown quickly on both sides, about 5 minutes. Combine reserved flour mixture, orange peel, orange juice, and sugar; stir well. Stir orange juice mixture into the skillet; cover, reduce heat to low, and continue cooking for 25 to 30 minutes, or until chicken is tender. Prepare rice while chicken is cooking. Spoon hot rice onto a serving dish; top with chicken pieces. Stir orange pieces and green onion into the skillet; heat through. Spoon a little of the sauce over the chicken and serve the rest on the side. Serves 4 to 5.