Parish records are pretty much essential when it comes to family history research. I actually got involved in research when I was 13. My father had the idea of taking me to the Gloucester City Library, which housed Bishop’s Transcripts (BTs). Now, BTs are not parish records, just copies of them, but similar nonetheless. I loved the ability to touch and hold the records in my hands, as well as the detective aspect of the research. I’ll do a separate post on BTs, but thought you’d be interested in that experience of mine as a young boy more than 50 years ago.
Parish registers contain information about baptisms, marriages and burials within the parish. If you;re lucky, you may even get access to the banns books. You won’t find anything earlier than 1538, and you probably won’t find very much at all from the Great War (First World War) onwards, but that still leaves you nearly 400 years of records to sift through. Admittedly, a lot of records were simply not kept during the Civil War, especially in areas held by Parliament, and many records have also been lost to mould and rats due to poor storage conditions, but enough is left to make the search worthwhile.
All of the examples I will give here are from Maisemore in Gloucestershire, but you will likely find similar things in the area you are researching if they are online. And I will make another post on how to get at theses records online.
The oldest records are often in Latin, or a mixture of Latin and English. Coupled with an often spidery hand, they can be difficult to read and interpret. Take this example from
1538, the very first entry in the register. It says “Anno Domini Secundum curium computationem eccleciae MDxxxviij Imprimis Johannes Fortie sepulte fuit xxi die May” which translates roughly as “In the Year of Our Lord according to the calculation of the church 1538 First, John Fortie was buried the 21st day of May.” You very quickly get used to what the words mean.
It took a while, but registers eventually began to be kept just in English. In Maisemore, that was not until 1734. Here is the first record in English. I think the writing is clear 
enough that it does not need to be written out, although some of the letter shapes are a little unfamiliar.
It was common to record Baptisms, marriages and burials in separate books. By 1754, marriages were supposed to contain more information. If you’re lucky, you’ll also get the
banns of marriage information, as in this example. Note that John was able to sign his own name, whereas Mary had to use a mark.
Finally, the Act of Parliament known as Rose’s Act required baptisms, marriages, and burials to be recorded on preprinted and numbered forms. In a way, this was something 
of a disappointment, because Rose had wanted much more comprehensive information to be recorded, such as full names of parents including maiden name of the mother, the names of the grandparents, and the actual date of birth of the child. Even so, it’s nice to have the additional information such as the father’s occupation and place of abode.
One final change for parish records was the Births and Deaths Registration Act 1836. As a result of civil registration, the marriage register now contains the exact same information as the marriage certificate. That’s not very helpful for those marrying outside the Church of England, but very rewarding if they did.
Family History research in England 