What a great place to stay! It's in the northern part of Amsterdam, an exciting area with old warehouses and industrial buildings now being re-used as bars/restaurants/art gallerys/flea markets/etc.
You reach the centre easily by (free) ferry and a 10minute walk from their home.
Nienke and Gert are two very lovely hosts, very helpful and funny. The room is on the top level of their house and huge. We had a great time staying at their home and would highly recommend it!