US Passport Application Information:
If you don't have a passport or if it has expired this is the most important trip prep site.
US State Department

Current Exchange Rates:
We watch all the exchange rates here and try to purchase when they are most in our favor. A little like playing the stock market. Once when we were still using ATM's the euro rate jumped almost 20% during our trip. Added a lot of surprise expense to our trip. Now we purchase foreign currency at the best rate we can get before leaving - no big exchange rate surprises.
XE: Currency Exchange

Airline Tickets:
We buy all of our flights online. Usually using Travelocity.
Travelocity
Expedia

Trains:
Buying train tickets online before leaving the States can save 100's of dollars.
Germany
Thalys - French service that travels to Belgium, Netherlands and Germany
For travel around Belgium
Belgian Rail Time Schedules
Italy

A few of our Fravorite Places to Stay:
Albergo Bernini, Siena, Italy
Podere Fontecastello, Montepulciano, Italy
Bed and Breakfast Bariseele, Bruges, Belgium
Ballinsheen House, Lisdoonvarna, Ireland
Holiday Parks, New Zealand

Museums:
Book tickets and make reservations for these and other major sites. Lines can be incredibly long and time consuming if you don't.
Galleria Borghese, Rome, Italy
State Museums in Florence

The official Uffizi site
Vatican Museum, Rome, Italy