From Amsterdam, it is 1 hour and 10 mins. travel with a normal train. An alternative is hispeed train called Fyra which takes you to Rotterdam in 40 minutes. However, there is a difference in train prices.
Upon arrival at the station, there are signboards pointing to the direction of the street parade. Tip: go to the direction of Witte de Withstraat. It is a nice location to watch the parade. Just like any carnival parade, it is such a delight to see this colorful and lively street parade. There are around 30+ trucks with different music, dj's, singers and bands. After every truck, there are big groups of participants dancing in the street with beautiful costumes. Participants and the crowd dance the afternoon away to the drumbeats and catchy music. They have the energy to keep on dancing from starting point to final destination in the city square of Rotterdam.
Here are video and photo impressions:
photo album 2011
photo album 2010