I will assume you mean ordinary people who aren't famous. As far as I know you would need to look in the paper registers at the Registry of Births, Marriages and Deaths. The records were held at St Catherine's House until 1997, when they were transferred to the Family Records Centre at Myddleton Street in North London.
I have found the following website useful. I think it only goes up to 2007 however. You have to pay online to use it but it seems reasonably priced.
http://www.theukelectoralroll.co.uk/
I think for up-to-date records you have to go in person to the Family Records Centre (maybe one day it will all be online).