I have found an excellent online financial news and commentary magazine, named PORTFOLIO.COM. Great stuff. Good explanations for simpletons like this NC Crone as well as in depth articles for the more financially sophisticated.
For some entry level explanations of "leverage" and "collateralized debt obligations" here is a link to PORTFOLIO.COM's graphical description of terms, as well as articles on how we got into the mess.
One article on the origin of these derivatives, "The $58 Trillion Elephant in the Room". by Jesse Eisinger, is at:
Whether you like finance or not, these are enlightening and entertaining columns and articles. One could spend hours just browsing.