Whether you have one, two, three days or more, Amsterdam has plenty to offer and more than enough to keep you entertained.
The canal cruises are a popular way to see the city from the perspective of its canals. There are many kinds of Amsterdam boat tours available. Romantic candlelight dinner, day or evening cruises, trips by boat to nearby garden village of Keukenhof and many more. Just have a look at the tours website mentioned above.
In about 3 hours the bike tour will show you numerous points of interest, offer lots of advise and insider tips and help you develop a great sense of orientation in Amsterdam. But Amsterdam has 214 rainy days a year and many others are cloudy so be avare of that. Bike tour operators count with this and you can cancel your tour up to one day before its scheduled.
While in Amsterdam we recommend an excursion to nearby towns and villages. Hague being more modern and exciting because of its role as the seat of Dutch parliament and many european institutions. Delft and Bruges are lovely historic canal towns great for evening walks and picture taking, while Zaanse Schans and Volendam are idilic cheese and fishing villages. Bruges and Zaanse Schans are also listed as World Heritage Sites of UNESCO so don't miss this opportunity to see them.
The bus brings you to the most famous sights in the city where you can get on or off as often as you like at the stops throughout the city. During nice days it even has open roof which is very interesting.