This site contains a huge variety of maps plus useful facts including demographics, economic data, and the history behind the subject of each map. Great tool for teachers and students.
This is another privately-run site. The chief qualification for the two men operating the site is that "both have lived in Ireland for their whole lives." This should be considered when using this site.
The demographic section is interesting; it has a map showing where most of the potato farming took place. I didn't realize it was concentrated chiefly in the western part of Ireland.
One more interesting website with lots of resources on the history of Ireland and its people; this specific site I've tagged is yet again regarding the potato blight. It some more images that could be used in the classroom.