Go to Use-it for the best tips about Rotterdam, it is a tourist information center for the backpacker who wants to discover this interesting City. You can find Use-it close by the train station. They have also a good website

Rottendam is easy to access by train. Hotels are in the city centre and around the train station. We found the Hilton Hotel was the best price, best location in the city mall area next to restaurants and shops. The needle down near the biggest shipping harbour in the world was offers an interesting view. Only stayed one night but saw enough. Clean city and seemed quiet safe as well.

Use your bike/public transport as often as possible. Traveling by car is expensive and takes a lot of time.

The VVV (Tourist Information Center) is next to the Rotterdam Train station that would be the best place to start with if you dont have much information about the city. Even if you have enough info, it would be a nice idea to strt from here since they could provide with you with travel tickets, offers, festivals or activities going on etc. The city is well connected with Metro, Tram, Bus their man-powered 3 wheeler :)

On my return from Delft to Geel I had to change train in Rotterdam and Antwerp. Used the opportunity to spent half a day in Rotterdam exploring the city.

Wonderful Waterways and the largest Sea Harbour in the world. Moderate climate.

consiglio di attraversare il fiume con il ferry boat e di andare dall'altra sponda a pochi chilometri nel paesino chiamato kjnderdike (o simile) dove potete vedere 19 mulini a vento antichi ma ancora in funzione che hanno aiutato a prosciugare l'olanda dalle acque del mare. si può anche fare una gita tra i canali in barca o visitare i mulini