As an American, I'll give you the general view of the U.N.:
It's a very weak, feckless organization that morally equivocates between nations. From the outside, it appears to be run like a fiefdom with diplomats trying to cash in while in New York. Not all nations are created equal. The U.N.'s goal should be stability through democracy. Not an easy task (just look at the Middle East). But the U.N. can start by not coddling dictatorships around the world. Pick a side.
I won't even get into the corruption with many of their programs. That has been documented elsewhere.
A reevaluation of their mission is warranted. I don't think their peacekeeping forces do much. In Africa, they have been disaster, and criminal in a lot of cases. During the Yugoslavian Civil War, many of the peacekeepers were taken hostage. In the Sinai, it has been successful because it was the Americans doing the heavy lifting.
Is it all bad? Absolutely not. I bet there are some wonderful people out there who are really striving for a better world. But when you look back at issues like Iraq's Oil for Food program and similiar attempts, all one sees is mismanagement and greed.