Travelling to Italy,Swiss, Germany.Guide needed please

Ok 3rd september it is. Me and my 2 other friends are booked to go to Italy. Flying down to Linate airport get a rent a 3 series and then go to Lake Lugano where we are going to stay ( its 15 min drive from swiss border ). Its a summer apartment of one of my customers and he is lettting me stay there for a week for a very cheap price.

I need help from anybody who is been to italy swiss or germany. I would want to know the places to visit in italy in swiss and in germany. Please give me as much information you might have thank you
-Sal