Very close to the train station, and David provided good directions to the apartment--10 minute walk. VERY lively area, with the Red Light district a block away, lots of foot traffic. That said, a canal is right across the street, and our apartment was in the back, so not too noisy. We walked or took a tram everywhere. Very nice cafes for breakfast right around the corner (omelets at one, German pancakes at the other).
Anne Frank house is a madhouse of tourists, as is the new Van Gogh museum (Sunflowers is there--wow--but remember, Starry Night is at MOMA), unfortunately. Rijksmuseum is fantastic, well worth the cost. Just walking around the city is great. Take the free ferry outside the train station and explore across the water and explore the new(ish) EYE Filmmuseum, as well as all the new construction.
Amsterdam is frenetic. The word "chaos" comes to mind, with all the motion, a zillion bicycles, a hundred languages, and--unlike other Euro cities--pedestrians to NOT have 'right-of-way' over cars or bikes. It can be a really fun, exciting city, but--especially if you're middle-aged or older (as we are)--keep your eyes open and have a good sense of humor.
And David's apartment is a really well-located base from which to do Amsterdam exploring.