GiveWell is a charity that evaluates other charities to try to find which do the most good per dollar: http://www.givewell.org/charities/top-charities

Please read my comment above. I lost hope on these UN and NGOs since I interned at a few INGOs (three) before going to college. I'd certainly recommend you to donate to charities that gives directly to the people (not the middle management and people who work) and the ones that have good transparency record.