Since a company's annual report provides so much financial information, it is one of the primary sources you should look at in analyzing a company.
FIS Mergent provides annual reports for over 10,000 public U.S. based companies.
Usually, you can find a company's annual report on its web site. Look for a link for investors or investor relations. Sometimes, it can be found under the About us link.
Below are some web sites you can also research:
About: Investing for Beginners: Free Annual Reports
Carol World: Annual Reports of Companies in the U.S., Europe, and Asia
Irin Annual Report Resource Center
Edgar SEC Full Text Search
If you use the Advanced Search Page feature, you can enter the company name, the type of filing you want such as the 10-K, the Standard Industrial Classification (SIC), and the Central Index Key (CIK). The full text goes back four years.
You can also try the a search at http://www.sec.gov/edgar/searchedgar/companysearch.html