Albergo Paola

This hostel is one of the best ones I stayed in while backpacking Italy and it's relatively cheap too. Located just a few blocks from the train station, the hostel is very colorful and modern. The best part is the amazing woman who runs the place. It's always spotless, she'll do your laundry (for a small fee), and there's an amazing free breakfast delivered right to your room! I stayed in a room for 4 people, but there's bigger rooms as well. Plus, there's a lounge with TV / DVD, a fridge, a coffee machine, and even a few PCs with internet that are free to use. The place is colorful, modern, and one of the cleanest hostels you'll find and the showers always have hot water. I stayed a week and have no complaints! Just make sure you realize it's on the third floor of the building and there's no elevator.

This place is amazing. I wouldn't suggest staying anywhere else. Think of it more like a bed-and-breakfast than a hostel. Clara is the best and keeps the place clean, safe and fun. Her cooking is great and her style of running her hostel helps create an environment where you get to know the other people who are staying there.

I used this place as a hub while in Italy. I was able to see all the sites ( < 30 min walk to Ponte Vecchio) and I was able to make day trips to Venice and Cinque Terre. The proximity to the train station (1 block) is great if you add on a few shopping pounds while in Florence.

Check out the full write-up here:
http://www.4tay.com/blogs/Adam_Parker/Italy_-_Florence_-_Albergo_Paola/1/1/674/

I've been to a few hostels in my time, and by far this is one of the best.  Clean and modern and well-maintained.  It's small too (only about 6 rooms), so it has a great cozy welcoming atmosphere.  But perhaps most amazing of all is Clara, the young woman who runs the place.  On her own!  She is beyond fabulous!  And not only does she manage one of the nicest hostels in Europe, but she cooks you breakfast (already included in room rate!), brings it to your room, lets you use the laptop to check emails, points out everything in Florence you could possibly want to see/do/eat/visit, and so much more!  She even made our beds once, lol.