well the train from Schipol runs to Centraal Station is quick (15-20 mins) and cheap - around €5. Could then take a tram from there - depends on the actual location though as to the utility of that. There is also a taxi rank at Centraal.

Depends how many bags you have as to how 'easy' it is but there are lifts and escalators to/from the platforms at both Schipol and Centraal.