The Public Access to Court Electronic Records, or PACER as it is affectionately known, is the online access system for dockets and other filings in U.S. courts. PACER includes filings from bankruptcy court as well as civil and criminal proceedings. Anyone can sign up. You don't need to be a lawyer, but it sure helps, as the PACER information contains a lot of legal mumbo-jumbo. But if you're willing to dig through it, you can find some pretty amazing information, or use the PACER Case Locator to see if your new business partner ever filed for bankruptcy.
You can sign up for PACER for free. There's a charge of 8 cents a page for every page you download (and that can add up for some of these dockets), but the fee is waived for minor users of the site.
Need more information? Newspaper archives are one of the best online research tools. If you're searching for information on people, try Intelius.