You do bring up a good point.
What exactly does it mean to help people?
Is it better to help a few people a lot, or many people a little?
I have done consulting work for NGOs and major multilteral organizations involved in development.
Some people have the idea that if you just give money to charity, you are helping people.
This is not always the case, due to many factors involving corruption, sustainability, etc.
The whole give a man to fish/teach him to fish thing.
IMHO, the best way to help people, particularly in a developing country, on a long term basis, would be to start a business in said country that is profitable, employ local people, and pay them fair wages.
IMHO, the best way to help people, particularly in a developing country, on a short term basis, is to specialized in surgery or tropical diseases, go to the developing world, and volunteer your time.
Oh, and if you want to see a horrendously depressing documentary, watch Darwin's Nightmare (no, it is not about the Tea Baggers).