The BP forums of course!! (not only literally, but some of the best resources out there!!) I like financial disaster books, and I think they're a great learning tool..
When Genius Failed: The Rise and Fall of Long-Term Capital Management - By Roger Lowenstein
I think there's a good lesson for all of us in being humble, understanding the limitations of own brilliance and prowess, understanding the limitations of "overly-calculating" prices and risks that all the data and math in the world cannot account for (no offense "big data" folk and economic statisticians)!, and perhaps the most important lesson that stands the test of time: the risk of leverage.
I think one of my favorite investing quotes comes from this book, regarding the squeeze that can take place when markets change and you're leveraged (think lack of refinancing, equity extraction, etc).. "The market can stay irrational longer than most people can stay liquid."
I wrote a blog post on BP about the risks/benefit trade-off on how leveraged you are over economic cycles, with some thoughts, considerations, and questions..
http://www.biggerpockets.com/blogs/4579/blog_posts/32645-if-ca-h-is-king-then-leverage-is-god---loans-cash-roe-roi-and-risk