If you're looking for examples of ineffective altruism (to illustrate the need for thoughtful giving) this somewhat sensationalist article has examples:
Horrifying Things Caused By Shockingly Naive Charities on Cracked.com. (I think I can't post a link because I don't have enough karma yet, but Google will find it.)
There are two links at the end of the article that also look promising.
Here's the link: http://www.cracked.com/article_23796_5-charities-that-failed-in-worst-way-imaginable.html