I find the files and maps available at this location to be invaluable in determining in which parish a particular townland was located, or conversely, what townlands were in a parish.
http://www.wexford.ie/wex/Departments/GIS/PDFMaps/There are multiple useful files and maps.
Also at the same location (same link) are maps showing the electoral divisions, which were also the historic registrars districts for births, marriages and deaths. (These are modern maps, there have been some changes, but still useful).
Following maps are also useful
http://wexford.maps.arcgis.com/home/gallery.html#c=organization&o=titleNOTE - I see that
aghadowey posted these back in 2009 - they are in the "Wexford Resources" sticky at the top of the page. But probably worth a post of their own, as many queries over the years show that people tend to be unaware of these resources (or at least they don't seem to ever refer to them).
