To book your theory test, visit: http://www.theorytest.ie/english/driver-theory-test/index.php
All of the information and study material is there to buy before you book your theory test. I would advise anyone to buy the book and the CD ROM. The book has the entire list of questions that may be asked but he CD may only have 80-90% of them. If you practice the CD ROM as much as possible and the list of questions is constantly changing well then you probably have covered them all. Most people will pass with the CD alone and reading the whole book can be too boring if you're not much of a reader. Once you are consistenly passing each sample theory test on the CD ROM, then, and only then, should you apply for the theory test.
The theory test is alot harder to pass than the very first edition over 10 years ago. It takes study and practice just like any other exam and some questions require over 4 answers. So if your attitude is that it will be easy to pass and you don't study and prepare well for the theory test you WILL FAIL IT. Aim to pass it first time and top marks of 40/40 is your goal. You must get a minimum of 35/40 to pass = 87.5%.