This page lists some general starting places for public company background information.
For private company information, you will probably have to rely more on articles.
For Company Background Information
LexisNexis Academic - Start with the "Get Company Info" box to search Company Dossier (lower right). For some info you may also need to search SEC filings. Find this option by opening the "Search by Subject or Topic" menu on the front page, just above the search box.
MarketLine Company Profiles Authority - Go toBusiness Source Elite and choose the "Company Profiles" tab from the blue bar across the top of the screen. These profiles of individual companies include sections such as key facts, history, revenue analysis, SWOT analysis, and more.
Standard & Poor's NetAdvantage - Lots of data and analysis! Use the search box at the top or choose the Companies option in the blue bar for more options.
ValueLine Investment Survey - Current financial info and an investment analyst's report. Choose "Browse Research" from the initial screen.  Use the search box just above the "Saved Screens" box: