A few safety precautions may prevent unpleasant surprises. Keep close control of your wallet, briefcase and suitcase at all times. Don't leave valuables in a car parked on the streets of Amsterdam.

The ticket for the use of all local public transportation is called "Strippenkaart". The number of "strips" required for a trip by public transportation depends on the distance to be travelled. The city of Amsterdam, and in fact all of the Netherlands, is divided into zones. If you travel through "n" zones, you must validate "n+1" strips. The validation must be made when you enter a bus or tram by having it stamped by the driver or by a machine. Within Amsterdam the strippenkaart can also be used in metro and railways. There are machines at all stations for validating the strippenkaart. If you have to take more than one bus/tram/metro to get to your destination, in principle you only need to stamp at the beginning of your trip.

A strippenkaart may be bought at railway stations, at post offices, on buses and trams from the driver, and at certain tobacco shops. When bought from a driver the price is higher than otherwise.

Some links with more information:
-Public transportation in Amsterdam (from the official Amsterdam city website)
-Amsterdam Public Transportation Information

-The Dutch evening newspaper NRC Handelsblad hosts a comprehensive introduction to the Netherlands for foreigners.

-You can also visit the official Amsterdam city website or the Amsterdam Tourist Board website.

-Or go to the non-official, but equally informative Simply Amsterdam website.

-For the Peeping Tom inside of everyone, you can check some Amsterdam Webcams.