The hostel is just a few blocks from Holland Spoor station, from which there are frequent trains to a range of other destinations in the Netherlands. To get into the centre of The Hague (Den Haag in the Netherlands), get a tram from HS station, or it's about 10-15 minutes on foot.
I stayed there for 1 night. The hostel has a canalside bar, with outdoor tables, internet access, cafe area and a well-staffed reception. There is some tourist information there but it is limited. Each guest is given a swipecard that allows them access to the front door, the lift and their own dormitory. There is no curfew. If you want to stay out after 1.00am, you need to get a night key from reception BEFORE you go out. Breakfast is served upto 9.30am. This was a buffet breakfast of cheese, meat, rolls, sugar strands etc. Check out is by 10.30am.
I stayed in a 4 person dorm. Each dorm has its own shower and toilet. The hostel was clean. Bedding is provided. The hostel has several two bedded rooms available. The long corridors give it an institutional feel. Dormitories are mixed sex, even the two person rooms.
I would recommend it. However, at 26 euros a night with my HI card, it was considerably more expensive than any of the other hostels I stayed in whilst visiting the Netherlands. While the facilities were good, they were not better than anywhere else I stayed, and did not warrant the extra cost. Unless you need to be based in the Hague, you could stay nearby for a lot cheaper.