I just got back from Rome and Florence and only had a EurRail pass for Italy so I can only tell you what they do there. Our pass was for 5 days of travel. For each leg of our travel we had to upgrade (pay an additional fee) to make reservations, and then pay another fee to take the EuroStar trains. We generally did both because the EuroStar trains are direct between big cities (no stops in tiny hamlets, making the trip much faster) and because we wanted to make sure we had guaranteed seats.
The advantage to having the pass you have is that you'll only have to pay upgrades and not the entire full-cost of a ticket when you get to Europe.
That said, make sure you purchase your upgrades and make reservations at the ticket counter. Don't use the automated ticket machines (Biglietti Volcere in Italy) or you'll have to pay full price.
You'll also notice that on your pass there is a space for travel dates. Only fill those in on your days of travel or you won't be able to use them at later dates. If you don't fill them in you'll be scolded by the train conductor.
Have a great trip!
PS - You may want to check out the forums for Amersterdam, Paris, Beuane, Florence and Rome on Trip Advisor. There's a lot of good advice out there. :-)
