We (5 in total) had a wonderful weekend in Amsterdam, staying in Anna&Marnix flat. It is a very welcoming and cozy place, in which we immediately felt home. Everything someone could just possibly need was there to find, including even more information over the city with maps attached. The lovely appartment being situated in a very family friendly, quite and calm neigbourhood with just a five minute walk to the pier where one of the "IJ" ferrys takes you to the other side made it even more attractive in our eyes. So location wise top, because it is also still very central.
So if your going to amsterdam, we would highly recommend staying at Anna&Marnix place, if you're lucky enough and can get your hands on ;)