It's difficult to rent a car, bicycle or scooter in Poggibonsi - the closest place is on the way to San Gimignano. The hotel staff will assist you, but ask well in advance as it take some time to get the bike to the hotel.
If you want to stay in a small Tuscan town with easy access to all the sights, Poggibonsi is great. It's very close to San Gimignano, but not as expensive. Albergo Italia is very close to the train and bus station and also close to the older, historic part of Poggibonsi. Staff were very friendly and helpful, although we had to use gestures at times. Our room was big enough and very clean, with a nice bathroom (looks newly renovated). Wifi is now available in all their rooms, not only public places. We had great meals at the restaurant next door, but it also seems that there are other good restaurants in town. Breakfast at the hotel was OK, but would have enjoyed a boiled egg or something extra (mainly bread, croissants, yoghurt and GOOD coffee).