The cheapest and fastest way to reach Amsterdam center is by train.
At Schiphol Airport take a train to Amsterdam Central Station.
This takes about 20 minutes and costs roughly 4 euro per person.
The trains leave about every 10 minutes.
A Taxi from/to Schiphol will cost you about 40 euro
Beware that there are many illegal taxi that tend to be quite aggressive towards tourists!
There is also an Schiphol Hotel Shuttle bus.
It takes you for 13.50 euro to many hotels in Amsterdam. Ask for the Avenue Hotel and you will be taken exactly to the corner of our street.