Florence - Florentine Sprint
You will receive this quest from a man waiting in the central district  near the cathedral.  The race should not cause any problems.
Florence - San Marco Scuttle
The second race in Florence you will receive from a man located near the eastern wall.  It is much more challenging than a previous one. You can not make any mistake here.  Think about the proper route and prepare your position. You have enough time here - speed is not so important here, the precision is.
Forli - Romagna Hustle
Man in the northern part of the city will give you this challenge.  The route is long.  In fact, however, it is not very difficult, and even if you will make some small mistakes, you can surely do it.
Forli - Horseplay
The second race in Forli is located in the south-eastern part of the city.  This time you will race on a horse - follow the markers.  It is not a difficult challenge - but remember not to hit some large groups of people or rocks. Horse will jump over a fence or wall, but not over a bigger elements.
Tuscany - San Gimignano Dash
Person with this challenge is on the top of one of the towers.  It is quite short, but intensive course. 
Venice - Venetian Rush
A man who will give us this challenge is located near the cathedral.  The quest is not particularly difficult, just stay focused in the canals.