So where have I got all the information from?
I started with the indexes of Births, Marriages and Deaths which used to be kept at the Family Records Centre in Clerkenwell. That involved a number of Saturdays when we went up to the FRC and went through every index for entries beginning "GUN" and noted down all the Gunnee entries (and any obvious variations). The indexes start in 1837 when they were written by hand and had very little information other than full name and location. They're all organised by quarters - which is why I might have a birth "about December 1851" which means the entry was in the index for Oct/Nov/Dec 1851. Later indexes started to include more info - so births would include the mother's maiden name, and deaths would have the age of the person when they died. I still have the spreadsheet we used to record all of the Gunnee entries & it has been the basis of the trees I have constructed.
It is possible to order copies of the original birth, marriage or death certificate - and these will hold a lot more information on the event but there is a charge, so I have only been able to do this where I've had no other option.
For entries before 1837 and other more detailed records I have used parish records, but often these are still held locally and although we've managed a few trips around the UK there are still some gaps to fill.
The next really good source of info are the census records. They go back to 1841 and are recorded every 10 years. Once you have tracked an entry down you get all the family members - ad in the later years their address, occupation place of birth etc etc. So a great tool for putting the individuals into families. Since I started the study the records for both 1910 and 1911 have been made available which has been a great boost to the families in the 20th century.