I love sites like Campaign for America's Future or Think Progress because they provide near infinite resources to the left leaning kind of people like myself that, in the past, were fighting so many of the big political arguments of the day without the benefit of any credible sources for research material. But they are not perfect.
Where else but Think Progress' The Progress Report are you going to find a page of material sent to you in your email inbox with pre-fact-checked material that is almost always timely and insighful. I.E. and from yesterday's (June 1st) The Progress Report: