I strongly advise staying at Iliaria's house if you want to visit Bologna.
It has a good location and you can walk to the main square in 13 minutes and to the train station in 15 minutes. During my 5 days trip to Bologna, I can visit every historical place by walking. As a house owner, she was very helpful in terms of advising me to local restaurants to eat, providing reservation paper when I was at the Visa Office before coming,..etc. Hope to visit again.
Bilgen