Bologna on bike

Hello, we are looking for opportunity to hire 2 bikes for 2-3 days during our stay in Bologna 25-27.04.2009 (arrival at 24.04.2009 in the evening). We come to Italy just for few days and we will not have our bikes with us, though we would appreciate to see Bologna from the bike seddle view. Can anyone let us know where can we hire bikes (can be commercial or private)? We would appreciate also some hints concerning cheap accomodation in Bologna.
Monika&Radek