Few Parish Registers survive before 1597 and some of the early Registers are written in Latin. Parish Registers may be viewed in different forms:
County Record Offices will be able to tell you whether there are indexes to the Parish Records you are interested in and will check and photocopy original entries for you inexpensively .CRO`s are contactable by e mail and should reply to straightforward enquiries .How this is interpreted varies and some will "go the extra mile " in trying to help.
Alternatively use a UK researcher to source the CRO for you. A reminder of where to find details about CRO`s - http://www.oz.net/~markhow/englishros.htm If you are unsure of the Church where the event would have been recorded take a look at this "Parish Locator ".It does not yet have universal coverage but it shows the complexity of searching of searching in Towns and Cities where there are many Churches within a small radius - http://www.genuki.org.uk/big/parloc/search.html If you have searched the Parish records near where your Ancesors lived and not found anything then consider the possibility that they were Non Confomists. However do NOT look for a marriage in a Non Conformist Church between 1753 and 1837. During this time apart from Quakers and Jews all marriages had to be at a Church of England, marriages were not valid if performed elsewhere.
Non Conformist Registers become more widespread after 1780 as Nonconformity grew. Again County Record Offices can advise which Registers exist and they will probably have a copy of these. Researching Nonconformist Ancestors can be more complex as fewer records survive . However for those who were active members there is sometimes a wealth of information in Church minute meetings, etc. The established Church of England obviously viewed the growing tide of Non Conformity as a threat although it is difficult to understand their antagonism from a Christian viewpoint.
Philip Westwood runs a genealogical service enabling Americans and Canadians to research their English Ancestors. For more details view his profile.