I'm planning a trip to Paris, Rome, Venice, Florence and maybe onwards to Interlaken/ Lucerne with my wife and two year old kid in early August. How do i go about making reservations for hotels, train/air? How reliable is the site www.hostelworld.com? Is it advisable to travel by train or take some budget airlines? Also, i've heard train tickets are difficult to get if making reservations at the last moment. Since my plan would not be finalized till about a month before the trip, would i be able to make reservations?