There are taxis on the island, though you need pretty good Mandarin or Taiwanese skills to negotiate a flat rate with the driver. They are also concentrated mostly in the city center, so you can't count on finding one just anywhere. Otherwise there are a few buses that run around, but they are not frequent and bus stops aren't particularly convenient. It is easiest to just rent your own scooter. You can get a 150CC for about 550 NT dollars per 24 hours. There is a rental shop in the airport. Roads are all paved and there are good maps at every village and in every hotel. Road signs are written in both Chinese Characters and English / Hanyu Pinyin, so it is hard to get lost.
