You can get a company's report and accounts in a number of different ways:
By writing to or telephoning the company and telling them that you are thinking of investing and asking for a set of accounts. Some large companies have an investor relations department for this kind of thing. Others will put you onto the company's registrar. Usually they will send out the latest report and accounts free of charge.
By using the services of specialist companies. e.g. McKay Company Reports (0207 395 5711), Investor Communications Business (0208 974 0200) or by using the services run by various newspapers and magazines (e.g. Financial Times, Daily Telegraph, Investors Chronicle).
Alternatively, you can get summaries of key historical data: