Where to stay in Florence, near rail line.

Try Venere.com. Honestly, historic center of Florence is so small, it's not far to walk from anywhere. Our hotel last October was by the Arno River, it took us 10 min to walk to the station.

Follow Ellen's advice.

Near the station avoid staying in the following streets/piazzas:

Piazza Stazione
via Nazionale
via Della Scala (the west part from via Santa Caterina da Siena all the way to viale Rosselli).
via Alamanni
via Jacopo da Diacceto.

The above streets have a lot of bus and light rail traffic, therefore they are noisier.

$100 is 70 euro. That will get you a one star hotel in the city center (maybe 2 stars off season). Nothing wrong with one star hotels, as long as you are aware of that and don't expect Sheraton type accommodations.

I always stay at the Archi Rossi hostel. While the main building is definitely youth hostel style, rooms in the Annexe are hotel-style. The only disadvantage I've ever found is the not very good breakfast that's included. But at the prices they charge, you can afford to go to a nice cafe instead. It's a 5 minute walk to the train station with luggage, yet a quiet street - and the quiet rule (11 p.m. to 7 a.m.) is enforced.

To get the best rates and choice of rooms, book directly through their website.