Anyone willing to take a long walk through the General Motors (NYSE: GM) 10-K, will find that the company got a "going concern" opinion from its auditors, Deloitte & Touche.

What the accounting letter says is, "The Corporation's recurring losses from operations, stockholders' deficit and inability to generate sufficient cash flow to meet its obligations and sustain its operations raise substantial doubt about its ability to continue as a going concern."

When analyzing a potential investment, one of the best places to find information about the risks is, amazingly, in the risk factors section of the company's prospectus or 10-K. While much of what you will find there is boiler plate and probably not worth worrying about too much, anything out of the ordinary (concerns that you don't find in the risk factors disclosures for most companies) might be worth looking into.

For instance, renowned short-seller Jim Chanos made a ton of money shorting companies like Party Gaming. In an interview with the Financial Times, he was asked how he knew to short online gambling stocks: "All I had to do was read the prospectuses of some of the companies that went public in London. They should have put a skull and crossbones on Party Gaming's . . . The prospectuses clearly said that under US law their activities may be deemed to have been illegal, which is what happened."

Companies disclose pretty much every risk imaginable in their risk factors, and a lot of times you'll find something that you might not have thought of. Sometimes, you can even find, as Chanos did, a risk that the market may not be recognizing, and have a potential short candidate.

To learn more about analyzing the risk factors, take a look at this recent article from the Wall Street Journal.

Herb Greenberg's Weekend Investor column focuses on the need for investors to be more skeptical or, as he calls it, detective-like. By looking deeper into the numbers than just the earnings per share or revenue growth, you can sometimes uncover signs of trouble before most Wall Street analysts do. And with increased disclosures as a result of the Sarbanes-Oxley Act, there may be more red flags to be found than ever.

Unfortunately, I suspect very few investors have the skills to read a 10-K or 10-Q critically. Most of us just take everything at face value. But, learning a little bit of "forensic accounting" is a lot of fun (you really do feel like a detective) and may help you notice some danger signs. Here are my favorite books for digging deeper into financial statements and seeking out signs of fraud or misrepresentation:

Financial Shenanigans: How to Detect Accounting Gimmicks & Fraud in Financial Reports by Howard Schilit. Probably the best book on accounting fraud.

Quality of Earnings by Thorton O'Glove. I found this one dry and boring, but it's written by one of the first experts in the field, and contains some great examples.

The Art of Short Selling by Kathryn F. Staley. While not exclusively about accounting fraud, this contains some interesting stories of companies that were engaging in creative accounting. And, if you become an expert on creative accounting, short-selling may be a way to a profit from it.