The explosion of e-commerce has led to a number of online stockbrokers appearing, who provide share information and the ability to practice trading. The source of share price information is an important factor, and in looking for an authoritative listing the London Stock Exchange would be a good option. In most cases however prices are time delayed, usually by around 15-20 minutes, though this varies from site to site.
Quotes are downloadable in Excel format.
The London Stock Exchange maintains a free Share Prices service which is available with a delay of 15 minutes through this service you can name the stock you want a price for, or just select the days largest risers and fallers. The Companies Index at Hemscott Net is a useful service to be aware of, with browsable indices of listed, AIM and techMARK companies. Each companies entry, when selected, gives some quite detailed share information combining both current and historical prices. The default screen displays the FTSE100 but a drop down box offers the chance to view tables and company share information for the other UK indices. Each index takes you through to a page giving further detail with closing prices for the index over the last year and index values for the past 10 trading days.