The Center for Democracy & Technology, one of the ACLU's coalition partners in the Patriot Act reform effort and other national security issues, has created a very handy resource page with hot documents on the NSA spying scandal.
Not only can you find a compilation of interesting news stories, there are also several key documents from the still-widening debate.
For example, you can see Senator Rockefeller's handwritten note to the administration expressing concern about the NSA spying program. It's rare to see a handwritten letter about a policy matter from a Member of Congress in this electronic age. The letter is a chance to see the Senator's thoughts unvarnished by staff filtering, because even staff with the highest security clearances were not allowed to be briefed! The letter is a rebuttal to the Administration's claim that Congress consented to the secret spying and did not express any concerns.
You can also see the opinion column by former Senate Majority Leader Tom Daschle about how the Senate refused to give the administration license to take the actions it did "in the United States" when authorizing force in Afghanistan in 2001.
Knowing what we know now about the misguided advice from the president's men, one can only imagine the types of martial law-like activities this administration would have considered permissible had the Senate not refused the President's entreaty on this point. As it stands, it's clear that the use of force resolution did not authorize the President to break criminal law and spy on US citizens without any check.
The site has a recent letter from conservative and progressive law professors that describes why so many people across the political spectrum are so very troubled by the President's actions. This helps demonstrate that the concerns that have been raised are not partisan and not political. They go to the heart of our democracy.
These are other key documents are up at the CDT resource page and I definitely recommend you check it out.