My family and I (6 people) are travelling to Italy in two weeks. We are flying into Venice and flying out of Rome. We want to do a wine tour in Tuscany and also a cooking class. Do you recommend that we book in advance or will we be fine if we book when we get there?
With a group of 6 reserve in advance. You are traveling during peak season.
On a separate but related note: I recommend making restaurant reservations - even if it's just an hour in advance especially for a group of 6. The usual drill in Italy is that they will then hold the table for you virtually all night.
Shirley has a good point. In Italy, once you're seated at a table, it's yours for the whole meal; they don't "turn the tables" as in the US. Because of this, once all the tables for 6 are taken, the restaurant will turn you away - for the whole night, not just for an hour. So, her tip about making reservations makes sense. If you don't have reservations, you will have better luck getting in right when a restaurant opens (this worked for me at a popular place in Bologna once - we literally got the only unreserved table, and saw lots of other walk-ins turned away).