Sarbanes-Oxley:
My colleague and fellow blogger Prof. Bainbridge has just published Complete Guide to Sarbanes-Oxley: Understanding How Sarbanes-Oxley Affects Your Business. I know nothing about Sarbanes-Oxley or corporate law more generally, but I know that Bainbridge is a top scholar in the field; if I needed to know about the subject, his book would be the first place I'd turn.