For extraordinary rendition issue

Probably check out the Amnesty International first, since they are a very large and respected organization actively dealing with the problem:
Amnesty International

You can also watch this FRONTLINE video from PBS (an American TV station) that should be pretty good:

FRONTLINE

Refer to this map from the Washington Post (a newspaper) that has a list of countries that participate(d) in the program:
Washington Post

This fact sheet from the ACLU (the American Civil Liberties Union, a human rights group that has been fighting for civil and human rights in America for decades) about extraordinary rendition:
ACLU

An article by the Director of Human Rights Watch written for the Huffington Post (an online newspaper):

CIA Secret Prisons

Another good article entitled "Outsourcing Torture" from the Huffinton Post:

US Torture Program

Finally, another article about how the extraordinary rendition policy of the Bush administration has NOT been cut back by the Obama administration:
Extraordinary Rendition is Torture