In Haarlem there are only two or three shops i visit. Near central station there's Trancentral where you can buy vinyl only. They sell some good records on occasion but mostly rubbish.

Then there is Key records in the Gen. Cronjestraat, I used to visit this in 89 en 90 when they sold good vinyl and some CD's. I was there a while ago, but it has changed into an "all music" store. They have some good classic techno CDs still, but no vinyl anymore (as far as i know).

Another small second hand shop that is worth visiting is in de Kleine Houtstraat, don't know the name (I think it has no name) of the shop. Here you can find some second hand vinyl and CDs in all categories. Not much techno but some ambient. The owner is Orb fan. Also some feed your head stuff here :)