This book by Barry Ritholz with a foreword by Bill Fleckenstein is the best book I've read on "how did we get there?" Ritholtz operates one of the most popular economic blogs, www.ritholtz.com/blog/. receiving over 50 million page views since launched. He assesses responsibility for the mess we are STILL in to 22 individuals or entities with Alan Greenspan at the top, the Federal Reserve #2 and Congress #5 with borrowers and home buyers (those who were misled or stupid or both as #7.
Describing Nouriel Roubini (find his credentials on the net) describes the book, "A beam of enlightened thinking in a sea of delusional complacency".
Greed, easy money, a corrupted Wall Street, unenforced regulation, incompetent "career" politicians, gullible investors (myself included) over-optimistic analysts, aggressive brokers; well, that pretty well sums it up. Well worth a read for all.