The Amsterdam Flower Market is located between the "Koningsplein" ("King's Square") and the "Muntplein" ("Mint Square").
One of the things to do is to walk down the Flower Market (in Dutch: "Bloemenmarkt"), a Dutch market of one of the products the Dutch are famous for: Flowers. It's an open-air market with all sorts of fresh flowers: tulips, geraniums, narcissus, etc.; flower seeds and bulbs.
The prices on the market are quite reasonable. Important thing to do before you buy flowers, seeds or bulbs is to look into what is legal to import into your home country. There are certain bulbs that can be brought into the US or Canada or other countries, other types that cannot. So always check that before you buy.
Even if you don't wan't to buy any flowers, it's always a nice stroll on the market. On the opposite side of the flower stalls are mostly souvenir shops. The market is open Mondays - Saturdays from 9 am to 17:30 pm and on Sundays from 11 am to 17:30 pm.