Shopping

Groceries
In the Netherlands you can find a lot of grocery stores. The cheapest ones: Lidl, Aldi, C1000, Poiesz. In the first two you wont usually find well-known brands - but it is still cheap. In the last 2 ones, you can find everything and home.brands as well. I personally do my shopping in Lidl or/and Poiesz.
The more expensive ones are Albert Heijn, Super de Boer. Of course if you do your shopping there, you can still find some nice discounts or the home-brands are also cheaper there (like everywhere).
These are all supermarkets, in Holland I have not seen any hypermarkets (like Tesco or Interspar), though I once saw a Spar in a village :D

Clothing:
Well, I dont do a lot of clothe shopping but my experience was that the cheapest ones are Bristol and Bentex. I once got a pair of jeans in Bentex for 4.50 euro. But it was because there was a discount:  2 halen, 1 betalen, meaning getting 2 for the price of 1. So me and my friend got two jeans and since both cost 9 euros, we got the 2nd one for free.
There is also H&M, C&A, America Today, etc. I dont usually go there so I dont know the rest actually XD
V&D is a 3 or 4 store building - you can buy there clothes, electronical stuff, there is also a restaurant/café kind place, junkstore -  every floor has its own thing.

Drugstores

In the Dutch drugstores you will find shampoos, medicines, pills, shower gels, deos - so everything what you would usually expect from a drugstore. My favourite one is Op is op, because it is really cheap and you can get well-known brands there. A pretty great place is HEMA. Thats also a drugstore but you can also get there some clothes (mostly underwears) and there is usually a small cafeteria.

Junkstores
My favourite ones: Action, Xenos, Blokker, Euroland.  You can find there EVERYTHING for a very low price. If you need blanket, or excercise books or whatever, just go there.

Of course there are a lot more stores in Leeuwarden, but these are the ones where I usually go to.

Oh, and maybe as an electronical store, I would mention MediaMarkt. Everyone knows it, no explanation needed, I guess.