The tourist office is on Via Vittorio Emanuele 80 (tel. 0922-970745). It is open April to October but keeps such erratic hours you'll never know what hours it's open.
If you wish, you can rent a bike at Autonoleggio d'Agostino, Via Bix 1 (tel. 0922-970755), and circle the island in a day. Bikes cost about 10€ a day, and motor scooters start at 25€.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.