For the sake of convenience the registers may be broken down into two categories pre and post July 1837, at which time national registration was introduced, however the registration of births was not compulsory until 1875 and prior to that date some records may only be found in the parish baptism records.
Post July 1837Free BMD is the workhorse of the post July 1837 registrations, giving the GRO Reference for recorded births, marriage and deaths. Whilst these are normally regarded as the source for obtaining the certificates, they can also be used for finding parish marriage registrations using Marriage Locator.
Marriage Locator is a new site which aims to decode the GRO marriage registration code to give the registration district and the name of the church at which the registration took place. Thus, instead of having to buy the certificate the details can easily be found in the local parish registers or using sites such as On-Line Parish Clerks (Genealogy) which are listed under parish and church names. Marriage Locator was set up by the Guild of One-Name Studies but help with this project is open to all volunteers, please contact firstname.lastname@example.org if you have access to local records, and wish to assist.
UK BMD is another site where volunteers have indexed the parish registers from within their counties, again from 1837. On going to the site, click the "Local BMD" button on the left and the counties which have taken part in this project can be found. Each uses a standard format and may include the reference for a local office from which a copy certificate can be obtained.
Pre July 1837The On-Line Parish Clerks project covers the earlier records as well as those post 1837. Usually it is possible to search all the records for each church, but not across all the churches in a parish. Hence it is better to try and establish the likely church for the registration. A number of the records contain an LDS film number, and it is not clear whether the LDS transcriptions have been used, or it is the reference for the microfilm in the local office - I hope it is the latter?
FreeReg aims to cover the whole of the UK, and probably has better coverage than other sites mentioned (except Free BMD post 1837). As with all volunteer projects coverage varies between different counties and parishes, however coverage has improved significantly in recent years. FreeReg probably gives more record details than other sites.
Of course, one site which must not be forgotten is Family Search, especially since the revisions which are currently in hand. It was on this site that after a number of years of searching that I found my 5th great grandfather, born in the early 1700s
GeneralWhen viewing all these sites it is worth remembering that they are secondary sources (unless the images are provided), and some of the originals, and not necessarily only the very old ones, can be difficult to read. The spelling of names may also vary, particularly if the informant was illiterate. Ages, especially for marriages, should be treated with care as some would have declared themselves as of "full age" when in reality they were under 21 and needed parental consent. Ages at death may be nothing more than a guess.
Finally, There are numerous small, e.g. family, sites which contain abstractions of parish registers. Many of these may be found on a CD available from One Stop Genealogy . The repositories for all registration districts are given by GENUKI.
© Ron Ferguson 2011