5 places
If you are taking a picture of the Oude Kerk please be mindful of the sex workers that maybe behind you. They get really nervous when they see a camera even though its not pointing in their direction.
There are lots of stalls selling food and drink - waffles, chips, smoothies, cakes and cheese. Other stalls sell clothes, jewellery and household stuff. Around the market are lots of side streets with nice bars (these bars are way cheaper than those in the middle).
Make use of the free shuttle canal boat, which takes you close to Rembrandt Square. While you're waiting for the boat, visit the local market, which is huge!
This is not a commercial area, only some private homes. It is free and somehow difficult to find - you have to walk through an unmarked door leading to this beautiful courtyard.
A walk around the neighborhood, along the Amstel and over a couple of blocks to the Reguliersgracht is very pleasant. There are a lot of great restaurants on nearby Utrechtsestraat. For an enjoyable evening, head over there for dinner and have a leisurely stroll around the canals after dark.