I cannot reccomend this book highly enough!
This book is not so much a travel guide (although it is that too to an extent) as it is a pocket sized, crash course in everything you need to know to truly appreciate your trip to Ireland.
This book is filled with wonderfull artwork and photograpy and contains sections on history, cuisine, geology, arts, flora and fauna, just about everything you'd want to know about Ireland and what makes it a special place to visit.
You will feel that you have a much broader general understanding of Ireland after you read this book.
The book itself is nicely sized for travel, with a solid, vinyl cover.
You will need a more detailed "travel guide" to compliment this book on your trip as this book does not go into many specifics such as directions to individual sites, route planners, times, fees etc. It is also lacking detailed local maps. For these things pick up a "Fodors Guide" which has them and IMHO makes the best Travel Guide series.