Last Friday, the Fed released the detailed transcripts of FOMC meetings during 2008, the year they realized the gravity of the financial crisis.  It's a big job, but if you are so inclined, you can read the transcripts in their entirety here. 

The NY Times has done us all a service by splicing key statements by Ben Bernanke, Janet Yellen, Timothy Geithner and others, along with the key graphics that chronologically show how the Fed has responded to the crisis.  One graphic tracks the evolution of the Fed Funds target rate (shown below) during 2008, as it dropped the target from 4% to almost zero. 

Janet Yellen was one of the first to sense the potential danger.  Here is a quote from January 21, 2008, in which she supports a historically large cut in the Federal Funds target rate:

I strongly support your proposal for a 75 basis point funds rate cut today... The outlook has deteriorated, not only since December but since our conference call.  The downside risks have clearly increased.  I think the risk of a severe recession and credit crisis is unacceptably high...

In hindsight, it is clear that Yellen was right on.