The certificates that record the most important events of anyone's life - their birth, marriage and death certificates - should be your first port of call when attempting to establish concrete facts about your ancestors. It's obviously easiest to start with known relatives.
'Once you've obtained your documents, the fun really begins.'
You will need to order duplicate copies of certificates you are interested in. Before you can do this you will need to obtain a certificate reference number - you do this by looking at indexes that are arranged alphabetically in quarterly chronological volumes, stored at one of several research centres.
The certificates for England and Wales are housed at The General Register Office in Southport, but the relevant indexes are available to the public at the Family Records Centre, London. A separate registry for Scotland is located in Edinburgh, at the General Register Office of Scotland, New Register House, whilst records for Ireland are divided between Belfast and Dublin - at the General Register Office of Northern Ireland, and the General Register Office of Ireland.
Once you've obtained your documents, the fun really begins. From a birth certificate you can obtain your relative's date and place of birth, the name and residence of their mother (and sometimes her maiden name - for you to follow up later). The name and occupation of the father is also added to the certificate.
A marriage certificate provides you with the full names of each partner, and the date of the marriage - more useful clues for further researches. You will also often find out the names of the fathers of both bride and groom.
From a death certificate you'll discover the date of death and final residence of your deceased ancestor. Perhaps of even more interest, though, is the name of the person who informs the authorities that a death has occurred. This is often a relative who can also be traced, thereby setting up another set of searches.