For publicly traded companies, information about company finances are often available via annual reports on the corporation's Website.
Google Finance also provides a good source for company finances. Enter a stock ticker symbol (e.g. NASDAQ:GOOG) and then click Financials. From the Financials you can get a quarterly breakdown of the Income Statement (default view) or annual breakdown. You can also view the balance sheet (quarterly or annually) from the Balance Sheet tab.
Business Filing Databases
Almost all of the states (U.S.) make some level of Corporate and Business filings available online. In a few instances only limited information (such as name availability) is retrievable. The majority of the states, however, use their Web presence to disseminate a range of public business records -- and most of them offer access at no charge.