Mario's place is located in the northern part of Bologna. If you land at the airport I would suggest taking the taxi as the simplest way to get to the apartment. If you arrive at the train station, you can either walk, but it will take 15-17 minutes and a GPS, or you can take the 25 bus near the station. It will take you really close to the apartment in minutes.
Once you get there, Mario or the co-hosts will welcome you for a tour of the apartment and the check-in. They thought of everything and they will leave small "attentions" around the place and in the fridge. AC works very well in all the rooms, as in the summer you will need it in Bologna.
They did their best to provide us with an extra baby bed and even borrowed a stroller for us to use while we were there.
Other details: the kitchen is fully equipped (dishwasher available), TV, washing machine, some shops around the neighborhood, but you can always take the bus to the city center and shop there. Calm surroundings.
You will have a nice stay.