Bamiyan town is small and walking is the best option. Around the region you can hire Toyota minivans for day trips from the stand in front of Mama Najaf's Restaurant. Also, along the road in front of the large Buddha is the tourist office in a pink building on the south side of the road and you can hire a guide. The guide is well worth it for the money.
The Roof of Bamiyan hotel also has vehicles for rent.