I've been trying to figure out how to choose an organization to donate to, given that there are so many.

I found this website that reviews charitable organizations on a few parameters, and it seems helpful:

http://www.give.org/reports/index.asp

It lists how much the CEO earns (eg CARE CEO earns $ 386,000). It also details percentage of organization income that goes to programs vs. adminstrative costs, and fundraising.

Any other infput that others have regarding where to donate (and where to encourage friends to donate) would be appreciated !

Give.org is coordinated by the Better Business Bureau, so it's a good source of information. Another site that rates organizations is www.charitynavigator.org - though their overall ratings include total assets, which may or may not matter to the giver. They have nice graphics to represent how donations are being used within the organization. Other useful giving sites include Network for Good and Global Giving.