Holland is all about wooden shoes (clogs), Delftware, tulips, t-shirts, chocolates and of course cheese!! So, don't leave that country without buying any of the above-mentioned items :) or you'll be sorry!!!
The most famous "typical" Dutch thing is a CLOG - the wooden shoe. They are sold everywhere, typically lacquered and adorned with some pretty designs. Another popular souvenir is a Delft white-and-blue ceramic. There are also models of Dutch ships and mills.
There are plenty of shops near the train station and along the Damrak.