This is a great list of what to look for in a hostel (slightly edited it here):
– Location (Club/Bar nearby, etc)
– Prices (per person, specials, etc)
– Is their a lock out?
– Does the kitchen close? What time?
– Wi fi? If not, what will you charge me for internet (if available)?
– Kitchen (clean, FREE food zone, available utensils)
– Let me see the room…lighting, carpet, test bed (ask locals about bed bugs), hangers, places to hang stuff, etc
– If dorm…can I secure my pack?
– Is their a bar inside the hostel
– Is their a common room without a television?
– any FREE meals
– Tradable book library?
– Extras to pay (not just leave a deposit on, but pay for): towels, sheets, secure luggage room or storage