Thanks to all for your help..
Fashionista007 mentioned that Keukenhof is closed from 21st of may onwards...any idea when it will open? Im going to be arriving sometime on the weekend of 18-19th July...so its still some time away....
Shinoo you say to catch the train to Amsterdam City Centre..is the station quite near to the airport? Are things written in english like stations and stuff otherwise im really gonna be confused :(