Whenever I need some quick pre-Famine background material in trying to put a family in their historical context, I go to the two volume work Topographical Dictionary of Ireland (1837): www.libraryireland.com/topog/index.php by Samuel Lewis. There are other dictionaries and gazetteers, but this is a good one to become acquainted. It has been reprinted, making it widely available in many libraries.
The majority of the entries in the book will be for villages, towns, cities, counties and parishes. They do not include townlands in this manner. It is written from a Protestant perspective, so the parishes mentioned are civil parishes. However, Catholic chapels and statistics are detailed.
I also use this source when I’m compiling a family history to publish. Sometimes, background information is hard to come by, especially for smaller places or for civil parishes in general. This dictionary does provide me a point from which I can write background history. For example, if I’m trying to determine how Patrick Sullivan met and then married Mary Kelly, and they were not from the same parish, this work will help. The section on the civil parishes where they lived will tell where the market towns were located and when the markets were held. That is usually my answer as to how they met when they didn’t live close to each other geographically. Remember, most of the common Irish were on foot and had limited mobility.
Lewis’s dictionary is a good launching point for your research. Just remember, it’s not the only resource of this type. I will talk about other dictionaries and gazetteers in the future.