Updated: Aug 6, 2022
List of recommended books including novels and textbooks, available from various websites online.
Buntus Cainte: https://siopa.gael-linn.ie/en/bunt%C3%BAs-cainte-123
This Irish book (leabhar) is one of the more popular ones which comes in three very impressive little volumes. Each of the books has two CD's, one inside each cover for listening comprehension exercises.
The benefits of the book are that the language is presented gradually, step by step, using cartoon-like drawings to show describe certain ideas, instead of English translations. To have the audio included is another benefit so that one can become accustomed to the spoken language.
Overall the book is well constructed using the built-in revision of words and topics whilst introducing new aspects in bite-sized pieces.
If you want to learn Irish (rather than learn about it) this is by far the best course I've found. Recommended reading age: 15+ years old.