If you are staying in Rome at all during your visit, we highly recommend staying in the neighborhood of Trastevere. It's quiet, full of cute restaurants, cafes, and wine bars, and it's close to just about everything in Rome.
We spent a couple days in Rome in March and became deeply acquainted with Roscioli in that time. They have three separate establishments: a bakery, a restaurant, and a cafe. All three spots are known throughout the city and came highly recommended by our BnB host. We hilariously went to all three. In short: excellent coffee, amazing baked goods, and, if you manage to reserve a spot, a pretty good dinner.
Villa Farnese is an ornate, Renaissance villa, located just north of Rome. We got caught in the rain here, but there was plenty to see inside the villa.
Villa Lante is a High-Renaissance "garden of surprise" full of centuries-old sculptures and water features. It is located in Bagnaia, a medieval town located about an hour north of Rome. Eric used to stroll these gardens with his friends during his year abroad in high school. Be sure to check out the walled portion of the old town, just across the central piazza.
Located on the way from Rome to Sinalunga, the Civita di Bagnoregio is a fabulous, crumbling town accessible only by footbridge. Only 7 people live there year-round, but there are plenty of places to eat lunch or get a quick coffee.