To get to know a city, it's always nice to go and check out a market. Stroll around, buy some, try some (cheese!) and enjoy watching the people getting their groceries.
Amsterdam counts 6 organic markets, and 3 of those take place on Saturdays. You will find only sustainable and organic products, some markets also have vintage clothing, books or handmade jewelry.
Close to the Haarlemmerstraat (a nice shopping street close to Central Station) you will find the Noordermarkt. A great divirsity in stuff - from organic farmer's products to vintage tableware, clothing, books and jewelry. If you find a spot, try to have some of Amsterdam's best applepie in the corner cafe called 'Winkel' (that means Shop)
This market is in the northern part of Amsterdam, it's a litte further out. For adventurers! To get there, rent a bike and take the (free) ferry from Central Station, it says 'Buikslotermeer'. From there it's a short bike ride, about 15 minutes. You can also take a bus from central station, a lot of busses go there. For example 33, 36, 37, 38, 46, 93, 100, 104.
The Nieuwmarkt market takes place on a cute square close to the red light district, and around lots of nice typical Amsterdam canals. It is walking distance from Central Station and you will find organic and local products.