How Many Shares to Issue

I was viewing a company formation website over the weekend and came across some references to authorised and issued share capital. Could you confirm exactly what the process is, the website made reference to 1000 shares at £1 per share?  Does this mean I have to pay £1000 for the shares in order to complete the registration of a company?

I am basically setting up a company for the near future and for running some possible contract work through it, but I am slightly confused.

If you are able to contact me and advise me on these issues I would be grateful.

Thanks, Graham.