Finding my family tree prior to 1800?

My 3rd great grandfather (William Angel Turner) was born in Needingworth,
Huntingdonshire in 1818 and married 'Mary'.

roy...

Sorry, I didn't read that properly before sending! I meant you need
to check whether his father was born in the same parish as he was,
mother also, and whether they were married there. Are there other
members of the family who appear in the registers? Don't just look
for parents but siblings, too, since naming patterns (Christian
names) often give a clue as to relationships, especially where you
are dealing with a common surname like Turner.

If his parents weren't married at Needingworth, then you must look
for the marriage elsewhere, starting with adjoining parishes and
moving outwards, extending the circle until you find a possible. Look
at work patterns and mobility within the area. People often moved
from one parish to another for work reasons. One particular thing
worth looking at are hiring fairs. These took place annually in
the nearest major town and attracted people from many miles around.
If someone from a village, say, 25 miles away was hired by an
employer from 25 miles in the other direction, then that might
account for a move between parishes 50 miles apart.

Roy Stockdill

"There is only one thing in the world worse than being talked about,
and that is not being talked about."

Oscar Wilde

I am now far enough back in my family tree that the online resources do not
appear to be able to help anymore.

roy...

1) Parish registers. Check them. If you can't find a Mormon FHC that
can obtain copies of the registers of Needingworth for you, or the
bishops' transcripts, you may have to employ a professional
researcher. Obviously, the first thing you need to know is whether or
not he was born in the parish in which he was married. What does the
IGI produce? If he wasn't born in the same parish in which married,
then the next logical step is to starting examining the registers of
contiguous (adjoining) parishes and see if he or other members of the
family can be found in them.

2) Wills. Many pre-1858 wills can be found at The National Archives'
Wills, if they exist, can be very valuable in establishing family
relationships.

Roy Stockdill

"There is only one thing in the world worse than being talked about,
and that is not being talked about."

Oscar Wilde

What is the process of now trying to find his ancestry?

Martin Brown...

Hunting through parish records on microfilm. Any tricks ot tips for
speeding the process up would be greatly appreciated.

A few places have partial transcriptions of their parish records online
if you are lucky. It all gets more difficult the further back you go.
And complicated if your ancestors moved about a lot between counties.

Martin Brown