How Can You start Investing in Stocks?

Each runner will have its own web page login through which you can operate, in fact, many banks offer direct investment and have web based interfaces.  

There is specific software that provides a smoother feel to the interface and perhaps a faster more reliable response, but again these are provided by the runners and each runner will be a little different. 

There are also  

Third party software that you can buy, but in reality the free web interfaces, often more than enough functionality for most investors. Runners UK address £ 's while the U.S. riders It's $ 's, which is the nature of the UK compared with the U.S..