to use the IGI as simply as possible, less is more ....do not put in too much information...
If you just put in Harpell, N.S. and look at the you can find extracted births for say Stephen's child, Lillianda and see that the mother is Annie Hopkins.
Next you can see if an extracted file exists for the marriage, try with her surname, then without...
Putting the parents only, no names ( in the First Name *Last Name )... into the database...say Luke Harpell & Lydia Arnold...will give you lots of names from submissions...
some of those results can be cross referenced to the tombstones and censuses...
You'll need a lot of paper... big tree!

have fun...J.J.