Several of the databases will help you research a company. Available data includes downloadable financials, share prices, Company profiles and SWOT analyses.
In the UK there is a network of Business and IP Centres in major cities, with the largest one based at the British Library in London. Most should provide access to some company databases. See the Industry Research tab for additional information, or the using other libraries tab.
Here are a few resources that may prove helpful.
Company registers
Listed Companies
Suppliers